A merchant navy or merchant marine is the fleet of ships which are basically tranport agents from place to place or country to country.  You need to appear any of one entrance exam like IMU CET conducted by Indian Maritime University, CUSAT CAT etc. for Merchant Navy.

IMU CET Eligibility: As per the Eligibility you must have passed their Class XII with an aggregate marks of 60% in Mathematics, Physics and chemistry. To check the complete information you can go throguh with given below link.

IMU CET Eligibility

CUSAT CAT Eligibility: As per the eligibility you should have secured at least 60% aggregate marks in Mathematics, Physics and Chemistry in class XII. To check the complete information you can go through with given below link.

CUSAT CAT Eligibility

The salary is based on your designation & your skill & performance but the minimum you can expect more than 35 to 40,000K.

Good Luck!