It's incredibly difficult to get into BUD/S as a ROTC guy. I had an ROTC classmate who was out of central casting for a SEAL candidate; high grades, absolute PT stud, leadership, etc. He didn't get a slot upon graduating, though I'm convinced he would have easily gotten in the door if he'd been from the academy. It all worked out for him though, he went to a DDG, did well there, got all his quals, and he started BUD/S shortly after pinning on his SWO pin. He's now in his 3rd operational tour as a SEAL officer. So if that's what you want, don't give up if you don't get a slot out of ROTC.