The final merit of the candidate is a cumulative weighted average of the following components:
CAT/XAT/GMAT (best score)
Academic Scores (Xth, XIIth and graduation) and quality/reputation and ranking of graduating college/institute/university
Performance in Personal Interview process in terms of above mentioned parameters
Work experience, both in duration and quality (for working candidates)

Officially there is not mentioned any minimum score of Graduation, I would suggest you to score well in the Entrance Exam to get into there. You can check the further weitage & more information about with the given below link.

https://www.imt.edu/admissions/pgdm/

Good Luck!