To be eligible for NEET, you should have complete your 12th with Physics, Chemistry and Biology as your core subjects. You may have Biology as an additional subject but should have Physics and Core subjects. Now what you studied in B.Sc holds no bearing as long as you fulfil your 12th criteria because NEET is written after 12th for admission to Medical, Dental, Ayush and Veterinary courses across India. There is no upper age limit for NEET. If you have studied your 12th with the above mentioned subjects and scored a minimum aggregate of 50% in Physics, Chemistry and Biology, you can appear for NEET. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST.