Hello

Since his percentile score in the exam is very low, he can prepare for the exam again and appear for JEE Main April exam with full preparation as best of the two scores will be considered. As he has scored well in Mathematics, he need to focus more on the other subjects (Aptitude test and Drawing Test).

He can join any crash course and also solving previous year question papers and sample papers will help a lot.

Do let us know if you have any other query.

Good Luck!