Hi.
Firstly for merchant navy you need to give CET this may 2018.
Then, coming to your query, fees vary from institute to institute. As Government institutes will be cheaper than private ones.
Government institutions will charge near about 2-2.5 lakhs per annum. Whereas in private institutions it will be 4-4.5 annum per lakhs.
The fee structure include hostel, tuition, food and some stationary.
I hope this helps.
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Good luck.