Yes, Maths is very well needed to pursue MCA. Be it in 10+2 or in your graduation level, maths is necessary to fulfill eligibility criteria for MCA. Different universities have different eligibility criteria but maths should be there either in 10+2 or in graduation or in both. Failing in which results into non-eligible candidate for MCA.
Maths is necessary because various programming constructs require maths in their background like Data Mining , Artificial Intelligence etc. We need to think logic of various Algorithms ex. in Data Structures.
So therefore, they tend to keep this maths section in entrance test also. In entrance exams some universities like DU(Delhi University) keep weightage as 60% for maths and 40% for other sections. However some will give equal importance to each section but none of the universities is there which don’t have maths as their crucial section in entrance test.