Hello there

Firstly I want to tell you that merchant Navy comprises of many departments and for all there are some slight variation regarding eligibility (of marks).

But I would tell you generally then if you're having at least 60% marks in PCM and 50% in English then you will be eligible for all the departments.

If I talk about the deck department(deck officer) then it requires 60% of marks in PCM and 50% marks in English of either 10 or 12 class.

For more information please refer the link:

https://www.careers360.com/careers/merchant-navy

I hope it helps you!

Thank you!