I believe rodeo is right...as long as they're doing paper time, they can't have contact with other felons. But just check with the parole officer. They can tell you for sure! If he's off probation or parole, then it shouldn't matter.
Despite being off parole (and way to go!) I would have to suggest that he clarify that with his old PO- There could be wrinkles like others who are off parole are perfectly fine but that he should not associate with current parolees (or that any friends currently on parole are not supposed to be hanging with him).... I expect that once off paper you can hang with whomever you want, but with the price of being wrong being a stiff one. I have to say "Contact the PO"