Hi

Is your friend overall pass?

If he has RT i. e Repeat in theory in biology, means he has failed in biology and thus failed in 12th.

And,

Without passing 12th he is not eligible for bsc or any graduation course.

So, I would suggest him to pass biology in order to be eligible for admission.

In case,

If he has Rt in biology but he has overall  passed 12th with 5 subjects and his result status  is pass then he can get admission in graduation courses which don't require biology require like BA etc.

So, being a PCB student with Rt in biology, even if he is overall passed,  he can't get admission in bsc courses but he will be eligible for BA courses.

Thank you