Who is niall horns girlfriends name arina From victorious?

Niall Horan is not publicly known to be dating anyone named Arina from "Victorious." There may be some confusion, as Niall Horan, a member of One Direction, has been linked to various celebrities in the past, but he has not been connected to a character named Arina. If you meant Ariana Grande, she is a well-known actress and singer but has never been in a relationship with Niall Horan.