Robert Pattinson plays the character Cedric in the Harry Potter movies. and Cedric dies in Harry Potter and the Goblet of Fire. So Robert only plays in the movies Cedric is in before the fourth Harry Potter movie.
No, Robert Pattinson doesn't actually come out in any other Harry movies, though in Harry Potter and the Order of the Phoenix Harry has dreams of the night he faced Voldemort and there are some scenes of Goblet of Fire with Robert Pattinson, but that's about it. :)