There is but it's The Ring not Rings. Actually, there has already been a prequel. It wasn't released in the states but it basically explained how Samora became the protagonist. It was ok if you're into the ring series.
However, Gutiérrez has responded to these rumors on Twitter, clarifying that Rings is not a prequel and in fact takes place 13 years after the events of The Ring. Since the first Western adaptation of the story was released in 2002, this places Rings in modern times.