Hello dear

I am sorry to dishearten but a ccording to the IIM admission criteria 2018-20, candidates appearing for CAT must have a Bachelor’s Degree with at least 50 per cent marks (for General category) and 45 Percent (for SC, ST and PWD category) or equivalent CGPA from any recognised university or c andidates appearing for their final year Bachelor’s degree examination can also apply.

So you are not eligible to give CAT(entrance paper for IIM) until you have graduated from a recognized university.