Legality of other courses while doing ca

I am pursuing CA and wonder whether doing concurrent courses, i.e., CS, ICWA, CFA, CMA or CPA is valid and leagal? Because, as far as I know ICAI allows only certain courses to pursue alonwith CA as mentioned in thier prospectus. I have seen many students pursuing many other courses alonwith CA. Kindly advise on future legalities and implications.

Thanks.