Hey Anubhab,

How to apply in Merchant Navy as an Indian citizen after class 12:-

• You have to clear IMUCET (Indian Maritime University Common Entrance Test).
• Admission is through the entrance followed by a screening test and a main written examination.
• After clearing the test, there is an interview and a medical test.
• Prior to starting the job, you must also undergo a ship-training course. The course is usually brief, and the candidates are taught the fundamentals of voyaging security.

l am providing the link for the official website you can check it for further information's.

https://www.imu.edu.in/index.php?id=5

Also for the exam syllabus you can refer this website below.

https://engineering.careers360.com/articles/imu-cet-exam-pattern-syllabus

Hope it helps.

Regards.