Actually, Ravuya was saying that he made a little gta clone for pc (it had issues, though) and that this could be ported.
Grandtheftendo is the nes game (a comepletly different game than Ravuya's).
Yes it will be a free nes rom.
Will it work in LJ?
Maybe, maybe not.
The reason why is the author, Brian Provinciano, was saying that he might use a custom mapper for the game, rather than a standard one.
That would mean that the emulator would have to have code to emulate this mapper. He said he would make plugins for the pc emulators, but that wouldn't help us. LJ would have to be updated to use it.