I want to know that maths subject is compulsory for apply ipmat entrance exam 2020
No, Maths is not a compulsory subjects in order to appear for IPMAT. Though the course structure will include maths, hence having maths as a Subject will be very beneficial. But in case you don't you're still eligible.
You need to score a Minimum 60% marks in class 10 and Class 12th boards or equivalent if you belonf to the general/OBC category. And a Minimum 55 % if you belong to SC/ST cayegory.
Best of luck