he's studying inter1year

Ok. You are in 11th class. There is no hurry. You can start with professional guidance from next year beginning.
For now you can start with basics like:
Newspaper reading,
Updated on news specially medical news.
You can even try sample papers. Analyse what section you can easily deal with.

The aggressive competition that surrounds NEET may be quite overwhelming. A genuine need to succeed coupled with a positive attitude will help you face the challenge without feeling the nerves; only strong-willed and determined candidates are the ones who ultimately make the cut.

You have lot of time and till then get good in your English (verbal and written) as well as a strong focus, practice and more practice can take you closer to your goal.

Good luck.