GMAT

Both are totally different streams and both have different scopes, comparison therefore is not possible. Just choose the one that you are really passionate about. Don't listen to people around you and get confused, otherwise you will go haywire. Just think, realize follow your dreams.

Any one from each.
Regards

Hello, well it depends where you want to study. Not all universities require GMAT or GRE. As an international student however you must take TOEFL or IELTS.
Regards

Dear Hemant, alongwith average colleges there are a few top universities too. Remember admission depends on the student's overall profile. Check University of Chicago Booth, UCLA, Babson College, Bentley, Boston University etc.
Best Wishes

Dear Shaunak, no accredited university will grant you admission without a GMAT and work experience. Therefore you will be required to take the GMAT.

Yes GMAT is required for you. You will only be eligible with a GMAT score. Aim for a score of 680-720.

time , ims are the coaching for GMAT exams

only practice make u win.in any field.so do it and go on.

There is no fixed answer to this. However you are seriously disadvantaged in terms of your percentages. To make up for that you will have to score really well in CAT. In my personal experience you will need at least 99.7 - 99.8 percentile overall. However the criteria to compute composite score changes every year and also the scoring depends on the incoming batch. But in general with 99.7-99.8 percentile you should get more than one call from IIMs.

Some of best institutions of the country accepting CAT/ MAT/ XAT/ CMAT/ GMAT are
1. IIM Ahmadabad/ Bangalore/ Kolkata
2. IBS Hydrabad/ Mohali
3. Lovely Professional University, Punjab
4. NMIMS, Mumbai
5. ISM, Dhanbad
6. Great Lakes Institute, Chennai
7. AIMS, Bangalore
8. Kirloskar Institute, Pune
9. Pune University
10. UPES, Dehradun
Check their websites for more details.
Good luck.