hi,

see according to josaa rules you must have secured 75% aggregate marks in 10+2 course to become eligible to admission in iiits, iits, nits and cftis. this 75% marks criteria is only applicable for general and obc category applicants, for sc/st obc category candidates marks criteria is 65% aggregate marks in 10+2 course. even if you donot have the required marks , if your marks in 10+2 course comes under top 20 percentile in your respective board exam then you are also eligible to apply.

also candidates must have studied physics, chemistry and mathematics as a compulsory subject in 10+2 course.

hope it would help with your query.

follow the below link for same,

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