It's definitely _alluded_ to in Player of Games, mostly as a method of emphasising how unpleasant the Azad society is, but I don't think we ever really _see_ any of it?
(I may just be forgetting; it's probably at least a decade since I last read it.)
If I remember correctly, Gurgeh's internal narrative reveals what he observes in one of the secret channels that are restricted to the upper class. Unpleasant is quite the understatement. lol
But yeah, I don't think we actually see it firsthand, it's more disturbing than gory.