I don't know whether anyone can help with this. It's a poor-quality scan of a photo given to me by a cousin and we don't know who has the original. My grandfather is on the far right of the middle row and, given his age (he was born in 1877), must have been taken in the 1890s or around 1900. My grandfather was in the Galway Town Rugby Football Club.
I'd be very grateful for any information that would help date it and it's possible there's a better quality photo somewhere, but I know the chances are small!