MBA Entrance Exam

With your expected CMAT Score of 140 - 150, given below is the list of colleges where you have a good Probability of getting selected:
Prin. LN Welingkar Institute Of Management Development & Research, Mumbai
Institute of Management Technology Nagpur
K J Somaiya Institute of Management Mumbai
SIMSREE Mu

No, once you are through with the test you don't have to give it again. Unless you want to improve your score.

The major part of CAT preparation is mock tests. Try practising mocks as much as possible. Keep your strong points on tips and work on weaker areas. Also, don't try to cover everything on the syllabus. Skip the portion that seems very hard. Try reading news articles. This will improve your VARC sect

https://www.shiksha.com/mba/colleges/mba-colleges-accepting-cmat-Lucknow
Get all the information from the link given.

After clearing your supplement exam, one can be eligible for CAT

You can check your admit card. It's written there.

https://www.shiksha.com/mba/colleges/mba-colleges-accepting-mah-cet-Tamil-Nadu
Get all the information here.

You need to match your score with their cutoff marks.

Yes, SNAP is mandatory.

You need to match your score with the cutoff list released by different colleges.