Yes. You are eligible for NEET. You can study Biology as an addtional subject and still be eligible for NEET. The same eligibility criteria applies. You should turn 17 atleast by December 31st, 2020 and you should secure a minimum aggregate of 50% in Physics, Chemistry and Biology. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST.