NSO: syllabus, mock tests and practice

How the exam works

Mode: Offline, objective multiple-choice paper held in school during school hours; each exam date has its own paper. · Levels: Level 1: Classes 1-12, held in the student's own school. Level 2: Classes 3-12 only; qualifiers are the class-wise top 5% internationally, the top 25 per zone per class, and school class toppers (where at least 10 students of that class sat the exam and the topper scored at least 50%). Level 1 questions are about 60% from the current class syllabus and 40% from the previous class; the Achievers Section and all of Level 2 use the current class syllabus only. · Duration: 60 minutes · Questions: Level 1: Classes 1-4 have 35 questions (Logical Reasoning 5, Science 25, Achievers 5). Classes 5-10 have 50 (Logical Reasoning 10, Science 35, Achievers 5). Classes 11-12 have 50 (Physics & Chemistry 25, Mathematics or Biology 20, Achievers 5). Level 2: Classes 3-4 have 30 Science + 5 Achievers; Classes 5-10 have 45 Science + 5 Achievers; Classes 11-12 have 25 Physics & Chemistry + 20 Mathematics/Biology + 5 Achievers. · Marking: 1 mark per question except the Achievers Section: 2 marks each for Classes 1-4 (40 marks in total) and 3 marks each for Classes 5-12 (60 marks in total). SOF's published pattern does not mention negative marking. · Language: English only

How to register

Only through the child's school: the school registers with SOF and sends the student forms, usually at least 30 days before its chosen exam date. Individual registrations are not accepted. Fee: Rs 170 per student per Olympiad incl. GST (India, Bhutan, Nepal), and schools may collect up to Rs 30 extra; US$11 elsewhere.

When it happens

Next Level 1 school dates: 19 November and 3 December 2026. Earlier dates (30 October 2026) have passed. Each school chooses one date; a future exam date does not mean registration is still open. SOF asks schools to submit registrations at least 30 days before their selected date. Level 2 is for qualifying Classes 3–12 only; SOF plans to announce the exact date by December 2026 and provisionally indicates the second or third Sunday of February 2027. This is tentative, not a confirmed exam date. Results are normally available within about 8 weeks. SOF now lists this science exam as International Science Olympiad (ISO); SkillStar retains the NSO category name. Status checked 1 November 2026; times are IST.

• SOF official 2026–27 schedule

Official website, syllabus and sample papers

Links to the organiser's own pages. Past and sample papers are published there by the organiser.

• ISO (formerly NSO) main exam page (2026-27 overview)
• Official ISO syllabus, all classes (links to each class page)
• Official ISO sample papers, Classes 1-12 (free PDF)
• ISO exam dates
• How to participate (registration, fee, levels)
• ISO FAQs
• ISO books incl. previous years' papers (paid, sold by MTG)