Every loves freshwater stingrays, unfortunately most of the rays in the hobby are the South American Potamotrigon species. Surprisingly, there is a huge number of Asian fresh water species that don't get as much attention as they deserve. They rarely show up in US or in Europe in aquarium trade. It might be something to do with the facet that they are much more fragile, more difficult to feed (they have smaller mouth), and require much more space due to their very long tails.
Most of the Asian species belong to Himantura or Dysiatis genus. There is some discussion as to whether they are brackish or pure freshwater. I think that most of the Himanture sp are pure freshwater, but Dysiatis are a mixed bag.
The most famous Aisan whiptail ray is Himantura chaophraya or the gian freshwater ray. It is one of the biggest freshwater fish right now. There was one guy from Singapore a few years who had it in his pond, not sure what happened later. I don't know any other ones in captivity, but it would be super cool if one of the public aquarium got one.
Here is the new born giant ray. Yes they are born small
Himantura chaophraya in captivity somewhere
Another captive giant stingray, notice the broken tail
And now for some normal sized rays. These guys actually show up in aquarium trad from time to time. So if you get a chance, definitely buy them. A word of warning, you CAN NOT mix them with South American species (well maybe only with small eyed rays such as Paratrygon sp, Heliotrygon, and Plesiotrygon). They are best kept in species only tank, as they have very small mouth and can easily starve or be bullied to death.
Himantura oxyrhynchus or the leopard stringray (notice very long tail)
Himantura krempfi - another leopard ray
Himantura signifer - white ribbon ray
Not a good idea to feed it goldfish, but someone tried
Himantura kittipongi- don't know much about this guy. i could not even find live pics of him
Makararaja chindwinensis -not much info on this guy either. I think he is from Maynamar
Some un-identified stingrays in a box
Dysiatis sabina- These guys are the only freshwater ray in North America (st. John's River in Florida). I know he is not from Aisa, but i added him here to show that he is closely related to the Asian ones. I have seen this guys for sale in US, but from anecdotal info, they are more suited for ponds because they produce an insane amount of urea and can poison the whole tank.