GATE

Yes, you may get calls from PSU and if you don't, then you can apply for the colleges. You can avail the scholarship of Rs.12000 per month.

The core branches like civil, mechanical, electronics, CSE, etc. has better scope.

If you have 3 years of experience then you are eligible for Institute of Engineers, India for M.Tech.

Keep your basic concepts of core subjects clear. Try solving the application based questions. GATE questions level is not very tough and easy to get through if you are sound with your concepts. Practice through writing tests. As the exam is nearing do revise the concepts and take tests.

Yes, BITS organize different exam for ME or M.Tech. You can also take direct admission in some private institutions for ME or M.Tech.

no u can also proceed without gate.

GATE is very competitive and best engineering students from all engineering colleges appear in examination. Therefore, any student aspiring to score high will be required to put lot of effort and hard work.

You should go as per your interest. Which field interests you the most?

It depends on your interest, GATE will get you in M.Tech and will help in enhancing technical skills, management and business skills. It will be a slightly newer course in MBA through CAT. I have done Masters in science with newer way of learning MS through GRE. You can try for the exam keeping in mind your future career prospective and your field of interest.