Can I do this course any time even after completing my graduation in other science field?
Candidates are offered admission to the course in India mostly on the basis of performance in a relevant institute-specific entrance test and the basic eligibility is -
Higher Secondary (10+2) or equivalent qualification, completed from a recognized university, in the Science stream, with Physics, Chemistry and Biology as main subjects and a minimum aggregate score of 50% or equivalent CGPA at the 10+2 level (45% for SC/ST/OBC candidates) so if meet this criteria then only you are eligible.
Good Luck!!!