Annamalai University (Distance Education), Tamil Nadu

After completing your Master;s degree with a minimum of 55%, you need to qualify the tests such as GATE/CSIR-NET/ JEST and TIFR /NEST /SLET, etc. If you qualify the written test, then you'll be called for the interview. In some universities, you'll be required to undergo their separate written test and interview. Ph.D is offered in two modes: Part-Time and Full-Time.
Part-Time: A candidate has to attend classes on weekends. Full-Time: A candidate has to attend regular classes (56 days a week). I am enlisting a few good colleges which are doing really well in this field of research. You can do it from:
Delhi University, University of Hyderabad, Jadavpur University, Jawaharlal Nehru University, Lovely Professional University, Jamia Mililia Islamia University, Banaras Hindu University, Aligarh Muslim University, University of Mumbai, Christ university, MS Ramaiah University, The Maharaj Sayaji Rao University, Anna University and Indira Gandhi National Open University (New Delhi).