When I breed barbs, I always condition my fish in sexually segregated tanks, that way the females get really full. To breed, I always use one male and one female in the breeding tank, female in first, male in just before lights out. They usually spawn as soon as it gets light, I cover the tank if that is going to be to early.
Tigers and their young are very susceptible to nitrogen pollution. Make sure you keep your water in tip top condition to get a good spawning.
Tigers are very fond of their own caviar. Even a thickly planted tank will not hide the eggs from the parents, so get them out as soon as spawning is over.