Hiii

In india, the marine biology course at UG level is BSc in Marine biology . This is a three year long course. The basic eligibility for this course is that you must have qualified class 12th with subjects Physics, chemistry and biology. And a minimum score of 55% must be obtained.
The admission to the course is generally based on the merit score of class 12th exam but some universities might conduct their own entrance exam
After the UG course, you need to go for PG course MSc in Marine Biology . It is a 2 year long course and gives indept study about marine science. The eligibility to apply to this course is a bachelors degree with minimum 50% aggregate marks.
The admission is based on university level entrance exams.
After Your MSc, you can pursue higher studies like MPhil in Marine Biology and PhD in Marine Biology .

Top colleges for Marine biology courses are as follows :

• Cochin University of science and technolog. kerala
• Karnatak Universiity
• Andhra Pradesh University
• Annamalai University
• Pondicherry University
• College of science and technology Andhra Pradesh
• Veer Narmad South gujarat University

Hope this helps
Thanks!!

Dear Arjun, if you want to study undergraduation in Marine Science there are 2 colleges across India. Government Science College Gujarat, Ismail  Yusuf College of Arts, Science and Commerce. Indian Maritime Unuversity Mumbai offers B.Tech in Engineering along with many other Institutes. For being eligible in B.Sc Marine Science, you should have completed your 10+2 in Physics, Chemistry and Biology with a minimum aggrrhate of 50%. There are more Master's programs in Marine Sciences than in Bachelors. Alternatively you can pursue B.Sc in Biology/Botany/Zoology and then pursue Masters in Marine Biology.