After the CAT exam result, all the colleges in which you have applied including IIMs makes a merit list to call students for the second round of interview, GD and WAT which is made in the basis of your aggregate score and which is based on different parameters such as CAT marks, 10th, 12th and graduation percentage, work experience, engineer or non-engineer, gender etc. whose weightage vary according to different colleges.

Except for IIM Indore almost in all IIMs, the highest weightage is given to the CAT marks but still, the previous academic marks plus work experience has a total weightage of around 20-30% which creates a big impact on your aggregate score and your merit rank.

So, it's recommended to have an atleast a decent percentage in 10th, 12th and graduation so that rest of the difference you can manage by scoring much more in CAT exam.

Then after you go through the second round of interview and WAT another merit list is made on the basis of the new aggregate score which also consists of the interview, GD and WAT marks. Generally, in this aggregate score interview and CAT marks have the highest weightage. Weightages of academic record is further reduced and you can catch up easily with your excellent performance in WAT and interview.

Priya if you can tell me your 10th, 12th and graduation percentage I will be able to tell where you stand and help you in a better way.