M.Tech

Indian Institute of Science [IISC], Bangalore and National Institute of technology, Karnataka are the best colleges to pursue M.Tech in Karnataka.

You need to appear for GMAT exam. You can apply for executive MBA in college like:
1. ISB – Hyderabad.
2. Great Lakes.
3. IIMs.
A score around 700 is a decent score to get calls from top B-schools.

Both the fields are same, but B.Tech in IT will provide you better career options. So, you can opt for B.Tech in IT.

Manipal University, IISC-Bangalore and PES University are some of the known institutes.
Check the below-mentioned link:
https://engineering.shiksha.com/me-mtech-in-karnataka-categorypage-2-59-1-0-0-1-106-2-0-none-1-0

You can look for jobs in public sector. You can try to look for openings in various public sectors like:
1. CONCOR.
2. ONGC.
3. SAIL.
4. HPCL.
5. ISRO.
6. BEL.
There are many engineering colleges, who needs M.Tech students as an assistant professor. You can opt for those opportunities and prepare for PSU jobs.

Aerospace is a good branch. You are already a technical student, so I suggest you to go with M.Tech and if you have interest in marketing, banking and accounting then you may go for MBA. But, as per my choice M.Tech in aerospace is better for you.

Yes, you are eligible for M.Sc in cyber security or information security. University of Madras offers this course. Instead of M.Sc there is M.Tech in cyber security. You can consider IIIT, Hyderabad too.

The best one is IIT, Hyderabad.

You can refer to the official website link:
http://www.aiet.in/AdmissionProcedure.html