For a masters degree in Environmental Science Central University of Punjab (CUPB) will be a better option. The research works conducted there are really good. 

The department has good motivated students and a highly experienced faculty. Even the lab facilities are good enough for education purposes. In Central University Punjab there is one more term added to the course, that is technology.

Central University of Rajasthan (CURAJ) is also a good place for Environmental Science studies but overall CUPB is better than CURAJ.