Dear Sreehari,

If you want to do Marine engineering from Kerala you can apply for Cochin University of Science and Technology, Kochi Ernakulam, Kerala and Indian Maritime University, Cochin. 

According, to careers 360 Cochin University has AAAA ratings which means very good.

Ratings are based on Faculty, Placements, Cut-offs of national / state level Entrance exams, Accreditation and Reward status and Publication record from Elsevier’s indexing database - Scopus

In order to take admission in these colleges you have to appear for your state level entrance exam for engineering. 

Good Luck!!