Hey Rohini, so few tips which i can share with you that might help you to prepare for your MSc entrances are:

1. Try and Solve previous year question paper. This will give you the idea of the paper pattern as well and will help you to gain confidence as well.

2. Also you can join a coaching institute, if you find yourself in the state of abiguity.

3. Plan your study sessions and try to keep up with the pace.

Also the attached link below will give you more details about more information about the course.

https://www.shiksha.com/science/course/m-sc-in-organic-chemistry-savitribai-phule-pune-university-ganeshkhind-274085