None! A tiger barbs in a ten would be a living hell for anything else in there including smaller tiger barbs. Nowhere to go. The half inch ones might be ok for a while but I wouldn't risk it.
well, if the tiger barbs were the only thing in the tank it would be ok. if thats the case, i would say 5 or so would be ok, but like fishysmell said, i wouldnt risk it.