Hi...

Total 490 seats  are reserved for the SC and ST category including all the IIMs.

Many says that getting 70 to 80 percentile will fetch you a good IIM , but is no the true fact because the competition is increasing every year for all the student even if you have the reservations. Even though the minimum cut off for the SC and ST students from the IIMs are 60 percentile but as the competition is increasing you must have above 90+ percentile in you CAT exam. This oercentile may even go higher because every year the quality of application pool is increasing.

The criteria for the calls from IIMs is still not known as it changes every year.Not only yiur CAT score is important but allso your academic scores and the performance in the writing ability test, group discussion and also the personal interview. You have quite good score in your grade 10 and 12 and try to get the maximum score in your under graduation as well,

Remember the highest percentile you get in the CAT exam , then there are higher chances of getting into the IIM. Do not get into the facts that reservation category can easily convert in IIMs.

Best luck