Colleges in Uttarakhand

There are 20 functional IIMs right now in the country. Every year each of them releases their criteria for calling students for GD/WAT/PI rounds. Though academic performance at school does make an impact on a student's chances of getting a call from the IIMs, it is to be kept in mind that it's not the only criteria. One can always make up in other areas like CAT percentile, UG percentage or work experience. As far as weight-age is considered, different IIMs weigh the scores differently while calculating their composite scores for the selection process. Since you are still in the first year of your under graduation, try to score as high as you can in the same and later in the CAT.
Since the criteria are subject to change every year, it's difficult to answer what percentage will be required in the year you appear for CAT.