That’s not true!
Anyone can pursue either of the courses coming from any stream/field. During my masters in TISS while doing MSW we had people who had done B. tech, Bsc in nutrition, Bsc in maths or economics and even masters in English etc. So, there is no such restriction.
However, when you will give the entrance test then you might have to practice math and quantitative reasoning. Otherwise math is not compulsory.