Hello,
I would like to bring this to your notice that for taking admission in any iim you are required to appear for the common admission test (cat). Overall there are 20 iims in the country . Each iim has its own way of shortlisting candidates.
Basic eligibility for cat exam is that candidates appearing for cat must have a bachelor s degree with atleast 50 % marks for genral category and 45 for sc,st and pwd category or equivalent cgpa from any recognized university.
Taking into account the percentile factor then the cutoffs go as high as 98 or 99 percentile. You need to really put all your efforts . Do remember that eligibility criteria for different iim is different. Some even consider the academic performance of a candidate like graduation mark etc.
I would recommend you to browse through the link given below to get an indepth knowledge about the same.http://www.google.com/amp/s/bschool.careers360.com/articles/iim-admission-criteria/amp
Hope this helps
Good luck