B.Tech

B. Sc in Nautical Science is a 3-year undergraduate course which is split into 6 semesters. Each year consists of 2 semesters and contains a thoroughly practical approach to all the concepts of Nautical Technology.
Whereas, Bachelor of Technology (B.Tech.) in Marine Engineering is a 4-year undergraduate course which is split into 8 semesters. Each year contains 2 terms, with each term a minimum of 6 subjects or more depending on the university.
A B.Sc. in Nautical Science fresher can take home a monthly salary of Rs. 50,000 as a deck cadet. Whereas, Entry-level junior engineers get between Rs. 25,000 60,000 per month in their training phase which depends on the company and role.
Comparing both the course, B.tech in Marine Engineering is better than B. Sc nautical science course. But, selecting a course depends on which field you are interested in.
Check both the links for full details about scope, job opportunities, syllabus, entrance exam, etc.
https://campushunt.in/blog/best-b-tech-in-marine-engineering-colleges-in-maharashtra/
https://campushunt.in/blog/best-bsc-nautical-science-colleges-in-maharashtra/
Thanks

Hello Santosh, It is indeed very nice to hear from you that in spite of working for a long time in the Gulf country your quest for knowledge has not diminished and you still are interested in pursuing your graduation in engineering. But unfortunately being in a Gulf country you can't do engineering from a recognised university in India hence you will have to first take a call weather at this juncture in your life you can spare 3 years for a full time course in engineering. If yes then you can come to India and seek lateral admission in an Engineering College based on your Diploma in your home state. If this is not totally feasible then you can perhaps think of doing associate membership examination of the Institution of Engineers which is equivalent to graduation in Engineering. Best wishes to you.