Rousseau was effective on a line with Gilles Tremblay and Henri Richard. I can't recall him ever playing with Béliveau, who had Geoffrion as his right wing. After Geoffrion was traded He centered Provost and Tremblay
Over the years of the 60s, there were many different combinations, depending on what year you are thinking of.
However, for the benefit of the readers who are a bit less "age-ful", Gilles Tremblay was a LW, and not RW.
For a couple of years, Beliveau played with Rousseau on his RW and Tremblay on his LW.
Before expansion, say 1965-66, these were the line combinations (you could dress 18 skaters, not 20 like today):
G Tremblay-Beliveau-Rousseau
Duff- H Richard-Larose
Ferguson-Backstrom-Provost
Cournoyer (PP specialist)
Roberts (PK specialist and also 6th D if needed)
Harris- JC Tremblay
Laperriere-Harper
Talbot