Ph.D

To know the Fee Structure along with Course Reviews, Cutoff & Eligibility of AVVM Sri Pushpam College, Thanjavur for 2022, please refer to the link given below-
https://www.shiksha.com/college/avvm-sri-pushpam-college-thanjavur-103135/courses

Refer to the link given below for cutoff information-
https://www.amity.edu/phd/

Here is the list of few colleges-
JMI New Delhi - Jamia Millia Islamia.
IIT Bombay - Indian Institute of Technology.
LPU Jalandhar - Lovely Professional University.
Christ University, Bangalore.
Jadavpur University, Kolkata.
IIT Madras - Indian Institute of Technology.

8 Ph.D. in Humanities & Social Sciences Colleges in Thanjavur. Find information related to Cutoffs, Placements, Courses, Fees, Admissions
refer link: https://www.shiksha.com/humanities-social-sciences/colleges/ph-d-colleges-thanjavur

The required minimum qualification for admission to a Ph.D. programme 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 55% marks or Equivalent Grade in the master's.

As Physics and environmental studies are kind of different subjects:-
I think it is not possible ( Try asking your professors they might help )
1) M.Sc. Or M.Phil in environmental Science and other related fields. Those with M.Phil qualifications need not attend the entrance test but other postgraduates have to appear for both entrance as well as interview. It takes a minimum of 3-5 years to complete the programme.
2) candidates should have passed M.Phil. Degree and a Post-Graduate degree in a relevant discipline with a minimum of 55% marks or an equivalent grade from a University or a recognized institution of higher training.

Do you want to know about the private or government colleges?