Hii Abhay!
You haven't mentioned the name of the Institution in which you wan to apply for oceanography course.
The eligibility criteria for the course states that the Candidate must have completed graduation with minimum 55% marks with subjects such as Physics/ earth science/ microbiology/ chemistry/ botany/ zoology/ agriculture/ fishery/ applied science etc.,
Then, the admissions may be provided on merit based or entrance exam criteria as per the College.
Hope this helps.
Good luck!