Dear Rahul, just clearing CAT won't guarantee your admission in IIMs. Your 10th, 12th, graduation marks and CAT score all will be considered during admission process. Since your 12th grades are low so try to score high in CAT exam to make your overall score balanced.
All the best
Hope this helps
Admit Card | Eligibility | Application | Exam Pattern | Preparation Tips | Result | Answer Key | Accepting Colleges
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile