If it's a two-person set...
There are several two-person empty-hand and weapon sets named Liuhe in Shaolin. In this case, Liuhe doesn't have anything to do with "Six Harmonies" but means "Six Rounds" which refers to the format rather than the style.
In these sets the pair comes together to "fight" and then splits apart and pauses, then comes back for another "round" with new movements. The are six such rounds, hence the name.
These two-person "Liuhe" sets can be from different subsystems in Shaolin, making their content quite different. Only the structure of the sets are the same in having "six rounds".