I have no doubt Jagr will play in game 6 but unfortunately for the pens he isn't likely to be a huge factor with the possible exception of the powerplay.It doesn't matter how great he is even Jagr can't score goals if he can't skate.
The rest of the penguins are gonna have to have a great game as they are not going to be able to rely on #68 to save the day. If Kovalev,Straka,Lang,Hrdina and especially Tugnutt play the way they are capable then the pens will survive to play in game 7 but they have to get the momentum back and they have to get the flyers frustrated like they were in the first 2 games and the best way to do that is to bottle them up and have tugnutt stifle them. If all goes well early hopefully the pens will be able to rest Jagr for game 7. Guess we will just have to cross our fingers and hope for the best eh peg.