At UG level, you can do courses in environmental sciences like:

B.Sc in Environmental Science : The course study must be completed with Science as the major subject. The candidate should have scored a minimum of 50% marks in 12th class examination from any of the recognized educational institutions. The selection procedure to this course is carried out on the basis of marks scored in the qualifying examination or through entrance tests.

You can even do courses like:

• Bachelor of Environmental Management
• Bachelor of Science in Environmental Science & water Management

Some of the diploma course you can do at UG level in this field are:

• Diploma in Environmental Science
• Diploma in Environmental Law
• Diploma in Environment Protection

Hope this helps.
Good luck!