llo,
The CMAT selection procedure will comprise:
Group Discussion (GD)
Personal Interview (PI) or Written Ability Test (WAT)
Candidates will be given admission on the basis of their performance in these rounds.
Well there is no minimum due to dyanamism. 
Well cmat cutoff starts from 99 percentile so you really need to score good in this cmat paper.
CMAT cutoff 2018 will be released by each participating institutes based on which candidates will be shortlisted for the selection procedure. In this articles, candidates will be able to access the expected cutoff of CMAT 2018.
Check this link for more information.
https://bschool.careers360.com/articles/cmat-cutoff
Cheers !!