Son will be at UT-Austin in the NROTC Marine Corps Option this fall. Reading through some the program material, it indicates that participation in other college activities is encouraged (meaning "have some fun"), but do not forget that you are here for a reason - NROTC - and that NROTC activities should be highest priority...in other words, don't miss PT, drill, etc in lieu of intramural sports or hanging out with friends!
I did also notice a mandatory 10 hrs of study hall per week for Freshman in the NROTC building (Steinham Hall). I think this is a GOOD thing. I attended UT back in the day and it is a HUGE university, easy to get lost "other activities". If I had been mandated to have 10 hrs of study hall, my first year may have gone a little better
UT and Austin are great though and would not have traded my experience for anything....Hook 'EM!