Hey

You can apply for JEE even if you passed 12 th from nios. Nios is given the same equivalent qualification as other boards.The eligibility criteria for JEE is that the applicants should have passed their 10+2 or equivalent examination. Students who are appearing for their 10+2 exams can also apply.The mandatory subjects are

B.E/B.Tech: The candidate should have passed the qualifying exam with Physics, Mathematics, and any one of (Chemistry, Biology, Biotechnology, Technical Vocational Subject).

B.Arch: He/She should have passed the qualifying exam with Mathematics, Physics and Chemistry.

B.Plan: He/She should have passed the qualifying exam with Mathematics.

Hope this helps.