Two ROTC Questions for Any Branch?

Wrong, you can do ROTC in grad school, it's just kind of awkward. It's simply a class you sign up for. Also ROTC is not 4 yrs, it's really only two but in order to be in the last two years you must do one of the following: A) complete first 2 yrs of ROTC. B) complete basic training/AIT(do guard or reserves) or C) take a 5 week summer course called LTC( google it). Since your in grad school and it's not 4 yrs, I would advise you enlist at your state's national guard, sit out a fall semester(take classes in summer) to attend BCT/AIT, and upon completion immediately contract ROTC becoming a SMP cadet.