Hello Riyaz,

In order to be eligible for IITs, NITs, IIITs, GFTIs, You should have studied 5 subjects-: 1-Language, 2-Physics, 3-Mathematics, 4-Any one of (Chemistry, Biology, Biotechnology, Technical Vocational Subject), 5-Any other subjects with minimum 75% in class 12th as a General category & 65% as a reserved category or you should be in top 20 percentile  in your class XII exam conducted by the respective board.

You can check the further eligibility to apply for the exam with the given below link.

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

Good Luck!