Is it possible for you to transfer a Rinnegan eye from one person to another? If not, is it possible to gain it through birth? I just have to know, because I'm trying to make a story about someone with the Rinnegan's son, passing the Rinnegan down genetically or just giving it.
If you literally take the eyes out and transfer them to another individual, then yes. Nagato's weren't his own and then there's Obito's as well. Sasuke also said that his eye could be given to Kakashi.