Hello aspirant,

Hope you are doing absolutely great.

So with regard to your query, YES you are completely eligible for JEE Mains exam. As per the eligibility criteria of JEE mains, candidate must complete his or her Mathematics, Physics and Chemistry subjects in 12th standard be it optional or main subject. Even you are eligible to give JEE Advanced as well.

For any details regarding eligibility criteria of JEE mains check out the following link: https://engineering.careers360.com/articles/jee-main-eligibility-criteria

Hope it helps you,

Good luck !!