There were 6. The Seneca, Cayuga, Onondaga, Oneida, Mohawk, and the Tuscarora which were more of part of the Oneida nation since they do not have any cheifs.
The Seneca, the Cayuga, and the Onondaga are three, but the other three are Oneida, Mohawk, and the Tuscarora, which are not exactly their own nation, more part of Oneida.