Hello,.
Candidates are short-listed for the admission process in different IIMs on the basis of theirCATscores. There are 20 IIMs in the country and each one of them has different admission criteria.
According to the IIM admission criteria 2019-21, candidates appearing forCAT 2018must have a Bachelors 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.
Candidates appearing for their final year Bachelors degree examination may also apply.
To get a detailed idea about how each different IIMs have their different eligiblity criteria, please visit this link
https://www.google.com/amp/s/bschool.careers360.com/articles/iim-admission-criteria/amp
Hope it helps