National Standard Examination (NSE) conducted by IAPT in Physics, Chemistry, Biology, Astronomy, Junior Science is the first stage for the international Olympiad.
All further stage are conducted by Homi Bhabha Certer for Science Education (HBCSE), Mumbai.
After NSE examination, next step for the eligible students is the Indian National Olympiad (INO) examination in the respective subjects. (For eligibility refer to students brochure. Statewise quota is available here.)