Hello Aspirant,

There is no any particular book for the preparation, For JNU M.Sc Environment Science , The questions will be of multiple choice type. The questions will be in two parts.

Part I: This will have questions from the different areas of Science and

Mathematics at the 10+2 level.

Part II: This will have questions, in the areas of Physics, Chemistry,

Mathematics, Geology, Botany and Zoology at the B.Sc. level.

You can also refer the below given link for the further information.

https://jnu.ac.in/admission/e-prospectus-2019-20.pdf

For BHU Entrance Exam, You can prefer the Graduation level syllabus & you can also go through with the previous year Papers to know the level of the Questions.

http://bhuonline.in/old-qus-paper-2018.html

Good Luck!