Ph.D

If your talking about distance PhD many universities do provide. IGNOU is one of the examples of universities which provide PhD facility and it's actually one of the best university in India to pursue online studies.

Indira Gandhi National Open University

PhD is done from from University not college. Make a list of universities and find out which ones are the best.

The required minimum qualification for admission to a Ph.D Program shall normally be a two years Masters OR M.Phil Degree from any accredited Indian or Foreign University in the relevant field. She/he must have obtained either a minimum of 50% marks or Equivalent Grade in the M.Phil degree or a minimum of 55% marks or Equivalent Grade in the Masters Degree (for all disciplines except Engineering and Technology), however, overall 60% at all academic levels will be desirable.

The first and basic qualification required for a Ph.D course is that you must have completed your Masters degree course.
To apply for Ph.D. you can either directly apply to the professors of different universities sending them your resume, Statement of purpose
and your research papers. Or you can appear for UGC-NET examination.
And then, sending your NET scores to the professors under whom you want to undergo your Ph.D course.

Admission for M.Sc-PhD Environmental Science and Engineering is offered through JAM with following test papers: Biotechnology/ Chemistry/ Mathematics/ Physics . If you can clear JAM after BCA you can seek admission in Sc-PhD Environmental Science and Engineering.