Board Thread:Theories and Speculation/@comment-734582-20150712141917/@comment-4136079-20150713214256

Thekillman wrote: It's not clear if Hagoromo possessed the Rinnegan since birth.

According to Black Zetsu, Hagoromo awakened the Rinnegan. Pretty sure that's sufficient enough. I mean, one wouldn't say, he awakened it if he were born with it, right?

Thekillman wrote: Considering the running theme, it's likely he did not and was in fact born with a Sharingan.

Agreed. I don't see any reason to believe otherwise.