MBA Entrance Exam

Yes in DTE process is also there in All India candidate quota which accept all exam scores (CAT, MAT, CMAT, etc). As they accept so many exams for only 18 to 20 all India seats, cutoff goes too high. Cutoff is 99.99 percentile (for all exams mentioned above) for general category. If any other query comment below.

You must score good in UG, to get into IITs for MBA a CAT score around 95+ is safe to get calls from the IITs. For IIT-B/D cut off is higher. Good academic profile is given priority during selection of MBA in IITs.

Any graduated may appear for CAT exam.

Dear Hardik,
Ideally, you need to have a minimum of 60% in graduation and above 98% in CAT. But your target should be above 70 or 80% in graduation (and 98%+ in CAT) because in IIMs rank calculation your graduation marks matter a lot.
Good luck.

The cut-off varies every year. There are no passing marks. There is a cut-off score required to have a valid score which is a dynamic process. It depends on how has the overall group performed. But to get a great college, you'd need to have a percentile above 85 in all the sections.

Following are the good coaching institutes for you:
StudyMBAIndia
Professional Academy
Climax Institute Pvt Ltd.

Hi,
Check out the below IIM call predictor which can help you find out which IIMs you are eligible for:
https://www.shiksha.com/mba/resources/iim-call-predictor

Hi Hardik,
Check with TIME, Career Launcher, IMS, etc. You can choose amongst the one all are good institutes.

If you are not opting for any coaching, then you can prepare by yourself using their study materials, which are available for cheap prices as second hand. As your level increases, you can buy Arun Sharma books to do advanced problems.