Academics are extremely significant at IIM Bangalore. If your academics are in the 70-85 range, even if you scored 100% on the CAT, your chances of getting a call from IIM Bangalore are less than 1% because it considers and gives very heavy weightage for both the 10th and 12th marks.
Score good marks in your Secondary and senior secondary exams. Prepare thoroughly and meticulously so that you can ace the CAT; this will increase your chances of admission to a good IIM.
The scores of class 10th and 12th board exams are extremely important for selection in IIM Bangalore.
Being an IIM Bangalore graduate, I can say that if your scores are less than 80% in both secondary and higher secondary exams then your chances will decrease significantly.
Even getting a percentile of 100 in your CAT exams may not be enough for you to get a call-up from IIM Bangalore if your secondary and higher secondary marks do not meet the minimum criteria. The institute lays a lot of stress on marks of the secondary and higher secondary exams.