At IIMA 70% weightage is given to CAT score and rest to  Application rating score which Includes Your class 10th 12th and Graduation. and Extracurricular. At 58% you will be given around 2 rating which one could get up to 10 so You are at the loss of 8 points which would be counted as 10% in the total merit calculation. It means you are 8 points behind those who have scored 90 percent marks, To get Into IIMA you need to score above 90% in graduation and need very good cat score.