i have done b.com at government college in North East under Dibrugarh University and my graduation percentage is 50% .
Dear Subham,
First of all, I would like to tell you that IIM Calcutta accepts CAT exam score and they have certain cut off for each category, for the general category, it is 90 percentile. Any college accepting CAT score whether it is an IIM college or any other has basic criteria of cut off percentage for graduation, 12th, and 10th. For graduation, it is 50% minimum to even appear for CAT exam. Since you qualify the basic criteria hence you are eligible for MBA in finance and accounting in IIM Calcutta (you choose your specialization in the second year of the program)
But keep this in mind that IIM Calcutta comes in the first tier of colleges which makes it difficult to get admission. Since your graduation marks are not that great so to even get a call from IIM Calcutta for the interview you need to get excellent percentile in CAT i.e much more than 90 percentile and improve overall profile if it is possible.
I hope this answer solves your query.
IIMs take admissions on the basis of CAT score, academics and gd/pi performance. IIMs also take diversity factor into consideration while taking admission. Scoring 50% in graduation is too low to take admission in IIM as 15-20% weightage is given to graduation Mark's.
I will suggest you to prepare for CAT and score 95+ percentile.
It will not assure you to convert IIM, but you will get a very good college for sure.
Wish you all the best.