Is there an actual mafia family based in New Jersey as in the sopranos or do the five ny families simply just have interests in the area?

Yes, there are actual organized crime families that operate in New Jersey, historically influenced by the New York Mafia families. The Genovese, Gambino, Lucchese, Colombo, and Bonanno families have had interests and operations in New Jersey, often collaborating with local groups. While the New Jersey mob has its own history and figures, it is often considered an extension of the New York families rather than a fully independent entity like depicted in "The Sopranos."