IMU s in Chennai and Kolkata are decent ones

yes, of course, if you and your family is okay then merchant navy as a career is the best opion and has very scope in future.

some colleges are IMU, TOLANI,MANET 

Yes matrime is very best option for career. It pays huge amount of salary.
You can have exam of IMU, ( indian matrimime University) . It has best colleges in our country. It's best colleges are
1. IMU Chennai
2. IMU Bombay( b.sc nautical science).
And many more....
Thanks...

Certainly, Marine Engineering is a very good career option with great oppourtinities. Marine engineering technology and techniques are used to create cruise ships, oil platforms, and harbors, m arine engineers design the vessels that we use to navigate and explore the world's lakes and oceans. For an instance, the average salary for different posts in this field are,

• Fifth Engineer or Engineering Cadet: 35- 75k
• Fourth Engineer: 1.5 to 2.25 lacs
• Third Engineer: 2.75- 3.5 lacs
• Chief Engineer: 5 lacs and above

Some great universities and colleges that offer maritime engineering are,

• Tolani Maritime Institute, Pune.
• Vels Academy of Maritime Studies, Chennai.
• Maharashtra Academy of Naval Education and Training, Pune
• DMET, Kolkata

But in the end it entire depends on your choice weather you're interested in this field or not So all the best for that!!