I'm a bit of a nut about being geographically correct, so to me at least using cichlids from the same continent would be how I would stock.
I would use 2 of the cichlids endemic in India, either Etroplus maculatus, or Etroplus canarensus, they are also small enough to live in that size tank, and will shoal a bit.
They don't have long fin trailers, that the barbs would be apt to nip at.
E maculatus has been line bred, and a solid red version is available
canarensus below