Hello Ashwini,

It would be difficult to tell you the exact as cutoff varies every year depending on the various factors  like No. of Applicant appeared for the exam, Difficulty level of the exam, Performance of the candidates etc. As per the previous year, The cutoff score of Round 3 was around 21.67 for M.Sc. Mathematics as OBC category.

You can also refer the below given link to check the previous year cutoff.

https://university.careers360.com/articles/ccmn-cutoff

Good Luck!