If you remember the end to part 5, Tommy Jarvis looked to be primed to take over the hockey mask. That didn't go over very well with the audiences, so it was decided to bring the proper Jason back. Never mind that they made it a plot point that he had been cremated since his death in part 4. There's money to be made, so the film came back.
It has been some years since Jason's last real rampage. Crystal Lake has renamed itself Forrest Green and has made efforts to move on. Tommy Jarvis (Thom Mathews) has not however. With his friend Hawes (Ron Palillo) in tow, Tommy drives to a cemetery in the middle of the night. He has to see, with his own eyes, that Jason Voorhees is dead. Never mind that he put a machete through the killer's skull (Part 4) and the aforementioned cremation (Part 5), which would seem to answer most questions, but Tommy wants to be really sure.
Finding the grave, they dig Jason up. Tommy freaks out a bit and shoves a metal fence post into Jason's chest. Lighting does the rest and Jason is back. Hawes's heart isn't in staying there and it's quickly not in his chest after Jason punches him. Tommy manages to escape, but can he convince anyone?
Not by screaming and trying to steal weapons he won't; Sheriff Garris (David Kagen) and Deputy Cologne (Vincent Guastaferro) lock Tommy up. the sheriff's daughter Megan (Jennifer Cooke) arrives and pretty much tells us she's going to be the Final Girl.
Meanwhile, counselors Darren (Tony Goldwyn) and Lizbeth (Nancy McLoughlin) are lost in the woods when they come across a certain hockey masked fellow with a fence post in his chest. Jason (and his post) may be rusty, but he gets back into the swing of things.
The next day; after Megan introduces her friends, IE dead meat, who all happen to be working at Camp Forrest Green, we see Jason getting his roots back when he slaughters a group of paintball playing executives. Now properly armed, Jason makes his way back his old stomping grounds.
Sheriff Garris escorts Tommy to Jason's grave, only to find it refilled (with Hawes's body, unknown to them). Now convinced that Tommy is crazy, Garris runs him out of town. That's when the bodies start turning up. Can Tommy stop Jason again?
Formulaic and by now the film just feels also ran. The supernatural elements are an unexpected twist, but since the franchise didn't seem to have anything resembling consistency, why can't Jason be a superhuman zombie? They never said what he was before.
The film's other issue is it's (comparable) tameness. More jokes, no nudity, and even the violence has been toned down. Not completely worthless, but it's telling that they were grasping for ideas by this point.