Broly's only shown in the movies. The films were created after the dragonballz series itself, so it's kind of plus like an additional thing. The films don't actually fit well in the plot because they were created after.
If broly was in the montrer he would of came before cell. In the movie if toi notice Gohan is a teen younger than the cell saga. Looks about the same as when the Freeza saga ends.
