Hello there!

Hope you are doing fine.

MNS exam includes three sections:

General English

General Intelligence

And academic subjects ( Biology, Chemistry  and Physics)

So you have to prepare these sections.

You are in class 11th, so you have almost 1.5 years for preparation.

Study your course subjects like English, Biology, Physics and Chemistry with full concentration, this will help you in cracking exam.

For general intelligence, you can buy any book.

Also, you can slove previous year exams or mock tests for better preparation.

Hope it helps.

Stay safe.

Good luck !!!