Each IIM has its own admission criteria, Most of the IIMs give maximum weightage to Personal Interview and CAT score for admissions. However, factors like academic cut-offs, past academic performance, relevant work experience, gender diversity etc. also play a major role in the final selection. Based on all this factors the students are called for interview and WSAT round. 

Along with this CAT percentile if you perform well in the further processes, You can have the chances to get a call from Old IIMs.You can also prefer the below given article for the further information.

https://bschool.careers360.com/articles/iim-admission-criteria

Good Luck!