Yes, you can get admission to MCA in Jadavpur University even if you have not studied Mathematics in class 12 provided that you have completed BCA. Subsequently, the requirements for MCA are
Or
BCA curriculum includes Maths based electives and therefore does not make it necessary to have studied Mathematics in class 12. Candidates coming from BSc or BCom must have studied mathematics necessarily in class 12.
One major advantage of doing an MCA after BCA is that you get to choose between a 2-year MCA and a 3-year MCA. which is also known as literal entry specially for the students who are coming from Computer Science based graduation.
To be on the safer side, you can again give exams by filling out the NIOS form (National institute of open schooling) and can give exams for mathematics. In case your Bachelor subjects are not considered this Certificate will come to use.