HI,

SEE some university or colleges takes admission by entrance test or some institute takes admission on the basis of 10+2 marks. now if you have caste category criteria you may get some relaxation. for colleges like delhi univeristy, banaras hindu university has entrance test. if you have more than 75% overall marks in 12th exam and has 80% marks in biology then you have fair chances to  get admission in reputed institution.