I booked 2 tickets through Ticketmaster recently for the Bord Gais Theatre. The only options I was given was the row's, only when I selected a row and went to payment was I given the seat numbers, many were not good seats, at that point you could still cancel the order and start over again. I did this a good few times and eventually got reasonable tickets.
Tip; I have since learned that if Bord Gais Theatre is anyway handy, you would save yourself the €14 odd that Ticketmaster charged in fees by buying direct without fees from Bord Gais’s Box office at the venue, Mon - Fri, 11 am - 6pm. Same applies with the Olympia box office and possibly others.