Doesn’t look good imo. See the other recent post for a comparison with known genuine examples. The R is different, as is the direction in which the G was signed. Other letter look off too. Plus he stopped doing a star many years ago. Several of these signed poster look terribly off. The ones that Ringo is signing on a photograph shared by Gary look good, and such photograph where Ringo’s is signing a few doesn’t proof anything for the complete batch of posters.
the other thread: https://live.autographmagazine.com/forum/topics/ringo-starr-autogra... , plus there is long discussion on the Top Beatles Collectors group on facebook,