Hello Punitha,

B.Sc Environmental science is offered in these 5 colleges in Tamilnadu:

1.SCSVMV University,Kancheepuram

2.Kumaraguru college of liberal arts and science, coimbatore

3.Madurai kamraj university, Madurai

4. Periyar University, Salem

5. St. Peter's institute of distance education, Chennai

Hope this helped. All the best!