Thanks to the RTI Act, IIM B has made it public that your CAT scores do not have a weightage of more than a fifth when admission decisions are made by the institute.
IIM B always had placed a premium on academic prowess that spanned much more than the 3 to 24 months preparation that students do to crack CAT. They did and still continue to place a lot of importance to a student's long term performance starting from Class 10. So, if there is anyone out there in class X and has a long term aspiration of cracking CAT, then make sure that you score well in your board exams as they matter as much as your CAT scores will 5 to 7 years from now.
For those, who have crossed the 10th, 12th or graduation bridges (especially for those amongst us who crossed the bridge not so colorfully), hopes of graduating from an IIM need not come to an end. IIM Calcutta, at least till the recent past did not place much emphasis on your previous academic record. In fact, the Admissions Committee Chairperson has gone on record a couple of years back that CAT score is sacrosanct and a high CAT percentile is certain to get you a GDPI call from IIM Calcutta.
I can vouchsafe for that claim. I have had classmates who had scraped through their graduation. A gentleman with a 5 CG from IIT Bombay was a classmate of mine. Another gentleman who is presently the CEO of a fast growing IT company barely managed 61% in 12 standard board exam (Tamilnadu State Board) and graduated with a 59% as a BA Sociology graduate.
The trend continued much after I graduated from IIM C. A gentleman three years my junior graduated from IIMC. Before joining IIMC, he graduated from Calcutta University with a B. Com degree. He had an aggregate of a little over 45% in his graduation. Very recently, a student of mine with a 6.5 CG from BITS Pilani made it to the IIMC. However, at IIMC he made a vow to be among the top 20 and made it to the top 18 and is presently working for a world renowned Business Consultant.
So, for all those who cannot go back and correct your scores at school and college level, there are still few IIMs left that give adequate credit to one's CAT scores. A 99.7 + percentile is likely to land you calls from a few of the IIMs, IIMC including, I hope. This is probably your only chance to redeem past sins should you aim to seek an admit from one of the IIMs.
I wish you all success in your CAT endeavors.