OSSC CHSL Syllabus 2026: Prelims and Post-wise Mains Guide
The OSSC CHSL syllabus is published by the Odisha Staff Selection Commission in Annexure C of Advertisement No. 728/OSSC dated 2 March 2026, for the Combined Higher Secondary (10+2) Level or Equivalent Recruitment Examination for Specialist Posts/Services-2025. It has two parts: a common preliminary syllabus for all candidates, and a separate technical paper syllabus for each post in the main written exam.
This page lists the official topics for the prelims and for the Amin, Junior Fisheries Technical Assistant and Junior Forensic Attendant technical papers, shows where the stages overlap, and gives a phased plan to cover everything. For the prelims, OSSC names only the topic heads, so the sub-topics marked as suggested come from the 10th standard level the advertisement specifies, not from an official list.
Table of Contents
OSSC CHSL Syllabus at a Glance
Stage | Section | Questions | Marks | Time |
|---|---|---|---|---|
Preliminary exam | Arithmetic, Data Interpretation, Reasoning, Current Events, Computer Awareness | 150 | 150 | 2 hours |
Main written exam | Technical paper for the post applied for | To be notified | 200 | To be notified |
Certificate verification | No syllabus | - | - | - |
The prelims carries a negative marking of 0.25 marks per wrong answer. Section-wise marks for the prelims are not fixed in the advertisement.
Key Changes to Know
Post-specific mains: The 2025 recruitment covers Amin, Junior Fisheries Technical Assistant and Junior Forensic Attendant, and each has its own technical paper. Study only the paper for the posts you applied for.
Older post lists online: Some pages still show syllabi for posts from earlier OSSC CHSL cycles, such as Soil Conservation Extension Worker or AYUSH Assistant. Those papers are not part of this recruitment.
Mains detail still pending: The advertisement fixes the main exam at 200 marks but does not state the number of questions or duration. Expect these in the main exam notice.
Bilingual paper: Both stages are conducted in Odia and English, so you can prepare in the medium you selected in your application.
OSSC CHSL Preliminary Exam Syllabus
OSSC lists five topic heads for the prelims. The sub-topics in the middle column are a working checklist built from the 10th standard level stated in the advertisement.
Section | Topics to cover (suggested) | Start with |
|---|---|---|
Arithmetic (10th standard) | Number system, simplification, percentage, ratio and proportion, average, profit and loss, simple and compound interest, time and work, time, speed and distance, mensuration basics | Percentage and ratio, which feed most other chapters |
Data Interpretation (10th standard) | Tables, bar graphs, line graphs, pie charts, mixed charts, data sufficiency | Tables and bar graphs, then data sufficiency |
Logical Reasoning, Analytical Ability and General Mental Ability | Series, analogy, coding-decoding, blood relations, direction sense, ranking, syllogism, seating arrangement, puzzles, statement and conclusion | Series, coding and direction sense |
Current Events of National and International Importance | Government schemes, appointments, awards, sports, summits, reports and indices, Odisha-related news | The last 6 to 12 months of news |
Computer and Internet Awareness | Hardware and software, input and output devices, memory, operating systems, MS Office basics, internet, email, networking and security terms | Basic terms and MS Office |
Arithmetic, Data Interpretation and Reasoning are skill-based, so they reward daily practice more than reading. Current events and computer awareness are memory-based and quick to attempt. With 0.25 marks lost per wrong answer, your goal is a high-accuracy set of attempts, not every question.
OSSC CHSL Main Exam Syllabus for Amin
The Amin technical paper has two parts: concepts of geometry and mensuration, and interpretation of maps.
Concepts of geometry and mensuration
Introduction to geometry: 2D shapes (line, circle, triangle, quadrilateral, rectangle, square, trapezium, rhombus, parallelogram), 3D shapes (sphere, hemisphere, cylinder, cone, cube, pyramid, cuboid), important theorems and postulates.
Triangles: Types of triangles, centres of a triangle, congruence, similarity, perimeter and area.
Quadrilaterals: Rectangle, square, trapezium, rhombus and parallelogram, with perimeter and area.
Circle: Perimeter and area, radius, diameter, secant, sector, chords and tangents.
Coordinate geometry and trigonometry: Area tracing using coordinate geometry, and height and distance calculation using trigonometric formulae.
3D mensuration: Volume, curved surface area, lateral surface area and total surface area of the sphere, hemisphere, cylinder, cone, cube, pyramid and cuboid.
Units: Units of area measurement and their conversion.
Interpretation of maps
Map basics: Introduction to maps, map scale and ratio, coordinates (latitudes and longitudes).
Types of maps: Political, physical, topographical, topological, nautical, thematic and road maps.
Reading maps: Properties of maps (distance, symbol and direction), conventional signs and symbols, interpretation of topo-sheets, and index in maps.
OSSC CHSL Main Exam Syllabus for Junior Fisheries Technical Assistant
This technical paper has four subject blocks: inland fisheries, aquaculture, chemistry and biology.
Introduction to inland fisheries
Unit | Topics |
|---|---|
Unit I | Importance of fish, present status of fisheries (global, India, Odisha), types of fisheries: freshwater, brackish water, estuarine, riverine, reservoirs and lakes |
Unit II | Inland fisheries resources: rivers, reservoirs, lakes, bheels, wetlands, ponds, tanks and canals; brackish water lakes, lagoons, estuaries, mudflats and backwaters; inland fishery resources of Odisha |
Unit III | Economically important freshwater and brackish water fin and shell fishes: identification, food and feeding, growth, reproduction and migration |
Unit IV | Reservoir and lake fisheries, conservation of fish stocks, floodplain wetlands, fisheries resources of Chilika lake and Ansupa |
Unit V | Coldwater fisheries, fish catching devices, inland crafts and gears, fish aggregating devices |
Introduction to aquaculture
Unit | Topics |
|---|---|
Unit I | History, principles and importance of aquaculture, monoculture, composite and mixed culture, integrated aquaculture, species selection, sewage-fed and wastewater aquaculture, extensive, semi-intensive and intensive culture |
Unit II | Types of fish farms and ponds, farm layout and construction, soil types and analysis, seepage control, hatchery design, cages and pens |
Unit III | Pond preparation and management, weed and predatory fish control, algal blooms, liming, fertilisation, bio-fertilisers, stocking, feeding, fish health and harvesting |
Unit IV | Freshwater prawn culture, brackish water aquaculture, important finfishes and shellfishes, seed collection and stocking |
Unit V | Ornamental fish culture, catfish and air-breathing fish culture, integrated fish-cum-poultry, fish-cum-duck and fish-cum-cattle farming |
Chemistry
Physical chemistry: Basic concepts and mole concept, structure of atom, states of matter (gases and liquids), chemical thermodynamics, equilibrium including ionic equilibrium and pH, redox reactions.
Inorganic chemistry: Classification of elements and periodicity, chemical bonding and molecular structure, hydrogen, s-block elements, and p-block elements of groups 13 and 14.
Organic chemistry: Basic principles and IUPAC nomenclature, electronic effects, reaction intermediates, and hydrocarbons (alkanes, alkenes, alkynes and aromatic hydrocarbons).
Biology
First year units: Diversity in the living world, structural organisation in animals and plants, cell structure and function, plant physiology, human physiology.
Second year units: Reproduction, genetics and evolution, biology and human welfare, biotechnology and its applications, ecology and environment.
OSSC CHSL Main Exam Syllabus for Junior Forensic Attendant
This technical paper covers physics, chemistry, biology and computer fundamentals, mostly at secondary school level.
Subject | Units |
|---|---|
Physics | Motion; force and laws of motion; gravitation, pressure and buoyancy; work and energy; sound; light (reflection and refraction); thermodynamics; electricity; magnetic effects of electric current |
Chemistry | Matter and its states; atoms and molecules; structure of atom; chemical reactions and equations; acids, bases and salts; metals and non-metals; carbon and its compounds; periodic classification of elements |
Biology | Biodiversity; cell and its organisation; tissue system; nutrition; respiration; transportation and circulation; excretion; control and co-ordination; reproduction; heredity and evolution; sources of energy; environment; conservation of natural resources |
Computer | Computer fundamentals: uses, input and output devices, types and generations of computers, memory, computer languages, MS Word, Excel and PowerPoint, internet, browsing and email |
Physics and chemistry here include numericals such as mirror and lens formula, Ohm's law and combination of resistors, so practise calculations as well as theory.
Overlap Between Stages
Area | Prelims | Mains | How to plan |
|---|---|---|---|
Arithmetic and mensuration | Arithmetic at 10th standard | Geometry and mensuration (Amin) | Amin candidates should study mensuration once, to mains depth |
Computer | Computer and internet awareness | Computer fundamentals (Junior Forensic Attendant) | One set of notes serves both stages |
Data Interpretation | Charts, tables, data sufficiency | Reading scales and data on maps (Amin) | Graph reading practice helps both |
Science | Not tested | Physics, chemistry, biology (Junior Fisheries Technical Assistant and Junior Forensic Attendant) | Start mains science alongside prelims prep |
How to Cover the OSSC CHSL Syllabus
Weeks 1 to 4: Arithmetic basics and reasoning daily; start a current events notebook with 20 to 30 minutes a day; read computer basics once.
Weeks 3 to 8: Begin your technical paper in parallel: mensuration and maps for Amin, fisheries and aquaculture units for Junior Fisheries Technical Assistant, or school-level physics, chemistry and biology for Junior Forensic Attendant.
Weeks 6 to 10: Topic-wise tests for each prelims section and 20-minute sectional sets for Data Interpretation and reasoning.
Final phase: Full-length timed mocks, same-day analysis, and revision from your error log.
Pair them with the previous question papers available on the OSSC website to understand the real difficulty level.
Is There an Interview in OSSC CHSL?
No. The 2025 recruitment has three stages: the preliminary exam, the main written exam and certificate verification. There is no interview or personality test, so the final merit list is based on main exam marks along with your post preferences.
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