Finding mathematics postdoc opportunities in India
First of all, I am not an Indian, please take my words as a grain of salts. I'll provide what I know.

University Grants Commission (UGC)


  is a statutory body set up by the Indian Union government in accordance to the UGC Act 1956[1] under Ministry of Human Resource Development, and is charged with coordination, determination and maintenance of standards of higher education.


As far as I know, they are in charge of almost all of the high level education matters in India.

I did find one of their web pages Scholarships and Fellowships which lists many scholarships and fellowships in India, including UGC scheme for post-doctoral Fellowships (pdfs) (To be named D. S. Kothari Fellowships), POST DOCTORAL FELLOWSHIP TO WOMEN CANDIDATES (I don't know if your student is a woman or not), etc.

Hope this helps.