IIM

If you want to boost your career in the banking field then Iims will definitely provide good courses for the banking field but prefer Masters in business finance, MBA in banking administration or MBA in business analytics. These courses will also help you in this because most of the banking operations at higher levels include analytics as you have good work experience, you will get a good pay package.

M.Com and MBA are master Degrees I. e, post graduation. IIMs provide only MBA.

Yes, you will definitely get a call from TOP IIMs. To prepare for CAT, study hard any daily practice 4 to 5 hours in a day and also give a mock test to practice well.
Best of luck.

Yes, it is a compulsory process of any IIMs. Your CAT score is not enough even if you get 99 percentile.

Yes, if you complete your MBA from any IIMs, you will get the best placement because its a very reputed college. Your placement is depend on your performance in your marks and very important in your interviews.

Minimum your graduation marks require is 50% and if you score 96 percentile in CAT. Yes, you can get a call from IIM and then, you will be eligible for their GDPI rounds.

Yes, you are eligible, given that you have scored a minimum of 50% in your UG (45% in case of the reserved class).

No, it doesn't matter what Bachelor course or stream you have graduated with at all. That's why, a lot of B.Tech and other students attempt these exams. However, Your 10th and 12th marks are taken in account with your CAT score.

90+% in both 10th and 12th would be required atleast if you score 95 % in CAT exam. Your overall merit will determine your chances.