Tiger Barbs spawn readily in community tanks with good water conditions. They are very sensitive to nitrogen pollution, ammonia and nitrite should be zero, and nitrates low.
Spawning is one thing, getting the eggs to hatch and raising fry is another. Realistically, to breed them, (and many other barbs/tetras), you need to keep the males and females in seperate tanks, where they should be conditioned over a few weeks with excellent water conditions and high quality varied food, some live food helps if you have a safe supply. The water should be soft, mildly acidic, (6.5), and kept warm, 27C/80F. If you keep the sexes together, they frequently drop a few eggs, but never a large clutch as they are "emptied" quickly, you need to build them up for a large spawning.
The breeding should be done in a special breeding tank. This should be very clean, and filled with the same soft, mildly acidic water as the conditioning tanks. There should be a number of spawning mops in it, or several bunches of a fine leafed plant, Cabomba or similar.
Select a good fat female, bright colours, errect fins, no faulty markings and no damage, and put her in the tank the morning before spawning. Select a similarly good male and introduce him in the evening then turn the lights out. If there is a lot of daylight, cover the tank - you want them to go straight to "sleep" once the male is added.
They will almost invariably start spawning when it gets light in the morning, you will want to be around, if it gets light early, cover the tank and remove the cover when you are ready. The male will chase the female around and a good pair will produce up to 150 eggs, which are a little sticky, some will stick to the plants/mops others fall off. Whatever, watch them, as soon as they stop spawning, they will hunt for and eat all the eggs. At this point, remove them from the breeding tank and return them to the conditioning tanks.
Assuming you've got a viable spawn, the eggs hatch after a day or so, but feed on their yolk sacks for the first few days. After hatching add one or more, (depending on the size of the tank), well matured sponge filters. You want to keep the water very good, but not produce too much current, so more and slow is better then a single with a powerhead.
Once they are free swimming, after about 5 days, the fry are ready for feeding. They are large enough for newly hatched brine shrimp from the start, but a good sponge filter will also supply infusoria and rotifers for any smaller ones. A good quality liquid fry food can also be used.
Keep the nitrogen levels down! The fry are even more susceptible to poisoning then the adults, evn a small spike will wipe them out. The fry grow quite quickly, cull out any deformed ones as soon as they are obvious.
This recipe is the same for many barbs, (and tetras incidently), there are some exceptions, but it's a good starting point. I first bred Tigers with this approach in the late '60's and have used it ever since, (also with minor water chemistry modifications, characins, rainbows etc.).
, so you do this in an isolated tank or in a breeder net and pull the barbs out when they are done with their cig's and the male promises to call her in the morning 
