Information Technology

Yes, you can start a computer training institute. You need to set up the institute. You can take help of PM's Mudra Scheme too. All the best.

As you have already done M.Sc. IT, why are you interested in doing M.Tech. If you want to study further then do Ph.D. in IT or go for MBA or certifications.
All the best.

Go for testing or support profiles if you are not interested in coding. You can also go for hardware and networking related profiles.

Yes. You have a chance to become programmer. Start learning software programming, do some certifications and try switching to IT related roles. The main issue here would be with the salary you would be offered. As you have 10 years of non-IT experience, you would be expecting some CTC which might not be offered to you as you lack IT experience. So, as per me, switching to IT project management kind of roles would be a better alternative for you instead of switching to programming. You can keep learning programming and do freelance projects side by side.
All the best.

Start figuring out the colleges offering project management as a specialisation. Prepare and appear for MBA entrance exams like CAT, CMAT, XAT, SNAP, etc.
All the best.

Usually, one has to complete all the semesters from a single college. If you want to switch, you need to talk with your college authorities regarding it. If there might be a provision for that, they will let you know.
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Open Universities are flexible enough. You can enroll in the program of your choice and submit an application stating your problem.
Also, there are many open universities which provide online programs. Check them out. There would be provisions in Dubai too.
All the best

Admission to MCA is not given without any entrance exam. You can check out some private colleges like Amity or Sikkim Manipal. They might have separate admission process.
Government colleges will give admission only if you have given entrance.