Board Thread:Naruto Discussions/@comment-46702312-20200902014722/@comment-46854995-20200910190120

I believe that this idea Rinnegan users are immune Sharingan-derived Genjutsu comes from the comment from Black Zetsu that Sasuke was immune to the effects of the Infinite Tsukuyomi due to the Rinnegan. People took this as an implication that other lower level Sharingan-derived Genjutsu, including Itachi's Tsukuyomi, must not have an affect on Rinnegan users, which I think is a reasonable conclusion. Obviously there's no hard direct evidence for that, but there certainly is indirect evidence.