that's 6 Gallons (my guess it's 1 of mini fluval spec tank) you can do mini planted tank and go with some glow fish, red serpa, neon/cardinal blue...there are ton of small species that can fit nicely for 6 gallons tank.
Thanks for the replies. I currently have a shrimp tank sp don't really want another tbh. I would've thought there'd be more fish (nano fish) suitable for that size tank tbh.