You do have a great number of students having an average academic record in the above Top Management Institutes as well as at IIMs. Some even have a Poor Graduation Score, but again they have the qualities and communication skills to impress at an interview and perform brilliantly in CAT, XAT, NMAT and other Top MBA Entrance Examinations, to overweigh their Poor Past Academic Record.

I personally know one of my seniors at college, having around 80-90% in 10/12 and a 7 CGPA in Graduation, ended up with 99.91 in CAT and Cracked IIML and a couple of more Good IIMs.