Science Eligibility

Eligibility Criteria for admission in M.Sc in Marine Science in GU:
Minimum 40% required in graduation and Candidates must be a graduate from B.Sc. in Marine Science.
https://www.shiksha.com/science/course/m-sc-in-marine-science-goa-university-goa-other-288308

Eligible for what? Please specify clearly so that I can guide you further.

Candidate must be passed Bachelor's Degree from any recognized University or it's equivalent examination with any of the following subjects like Environmental Sciences, Chemistry, Botany, Zoology, Microbiology, Geology, Geography, Life Sciences, Fisheries Science, B.E. (Civil Engineering), Environmental Engineering.

For admission, you need to have passed 10th from a recognized board and must be minimum 18 years old.

You need to score the minimum scoring marks of PCB combination. In certain situations, your CS will be taken as optional subject and its marks won't be taken in account for biology seats. What you need to do is apply for admission while simultaneously preparing for compartment. By the time of admissions there is high probability that compartment result be declared beforehand.

To apply for M.Sc inter science, you are supposed to have B.Sc (h) degree.

Yes, you can take KCET exam, you are eligible for the same. Good luck.

If you are going through JEE Mains, the criteria for your eligibility is to have minimum 75 percent marks in class 12th that's it.

Candidates should have passed B.Sc with physics as major subject with a minimum of 50% marks in aggregate. Candidates should have a Bachelor's degree in management or commerce from a recognized university with a minimum of 50% marks in aggregate.

I hope this link will help you
http://nicfs.gov.in/?page_id=16816.