Marine Biology courses are mostly offered in Post Graduation level. For that one need to complete Under graduation with Biology as the main Subject. There are few colleges in India which offer M.Sc Marine biology-

Kerala Agricultural University

College of Fisheries, Kochi

The National Institute of Oceanography, Goa

Kerala University of Fisheries and Ocean Studies

Chettinad Academy of Research and Education.

In under graduation level, you can go for B.Sc aqualogy which is offer by a few colleges of India like  SHARDA UNIVERSITY, Lady Irwin College, Chawdhury Charan Singh College, G D Goyenka University etc.

Government Science college, Kutch, Gujrat offers B.Sc Marine Science.