Hello Chirag!
There are many competitive exams and olympiads wherein school students can participate. With respect to your query regarding class 11, here are a few exams which you can concentrate upon :-
• Kishore Vaigyanic Protsahan Yojana (KVPY)
• National Science Olympiad (NSO)
• International Mathematics Olympiad (IMO)
• National Level Science Talent Search Examination (NSTSE)
The syllabus for most of these exams or olympiads is of CBSE level and hence NCERT books are to be concentrated upon in order to perform well in these exams.
Hope this helped.
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