Leaving myself open for some heavyweight abuse here.........
The Nr will rise in turns in either direction due to load factor as GG correctly stated.
However, as the disc is tilted, there will be a transient increase or decrease in RRPM (CCW rotor - Nr increases transiently as rolled right) due to Vsquared effects on drag (and autorotative force) between advancing and retreating blades. The higher the airspeed, the greater the effect. Zero airspeed autorotation = no transient Nr change.
JJ