GATE

Hello.
Kindly go through the college predictor, through this, you may get predicted information about in which college chances of your admission are high. https://www.shiksha.com/college-predictor
Best regards.

Yes, if you have done B.Tech in mechanical, then you are eligible for aerospace in M.Tech without any flaw.

Without GATE score, you will not find any decent college. It is very important to find a decent college in M.Tech. So, please appear in GATE otherwise stay a year and do hard work for the GATE. The final decision is on you.

To take admission in government colleges, like IITs, you have to score above 97 percentile. For NITs, you have to score 80% to 97% marks. For government colleges other than NIT or IIT, you have to score above 75 percentile marks.

Hyderabad University, Hyderabad
Jamia Millia Islamia, Delhi
Jawaharlal Nehru University, Delhi
Pondicherry University
Tezpur University
Annamacharya Institute of Technology & Sciences, Andhra Pradesh
Auroras Engineering College Andhra Pradesh
Bapatla Engineering College, Andhra Pradesh
Babasaheb Naik College of Engineering, Maharashtra
College of Military Engineering, Pune.

If you have less CGPA in B.Tech, then you should score good marks in GATE exam, otherwise you will not be able to get admission in top colleges.

GATE is not for undergraduate courses. It is for PG. You have got only 48% marks. My sincere advise is to leave obsession with engineering and look for something different. Go with your passion. Commerce, arts, fine arts, there are different courses that you can choose.

You need to score a decent percentile (Above 98 percentile), as most students appearing in GATE are from CS stream.

Yes of course, GATE (Graduate Aptitude Test in Engineering) is for the admissions into IITs and other reputed colleges for M.Tech or ME courses.