Scarlet Badis are slow, deliberate feeders and very small as adults. So yes they can be with other fish, BUT only certain fish.
Other Nano fish that are calm and peaceful may work. Plus they prefer live plants. I just got my first Scarlet Badis ( scientific name Dario Dario) yesterday.
Mine is going into my Shrimp tank
View attachment 51286
temporarily until his tank is ready. He'll hunt baby shrimp but I have about 100, so it's ok if he eats some.
I will get more S. Badis once I see how he likes his final 10g. (it's cycling and plants are growing)
His intended home ( Betta WILL be moved out )
View attachment 51285
I'm adding driftwood and more plants this week.
Planned tankmates ?
Celestial Pearl Danios
more Scarlet Badis 3-4 ? I'm going to try to find females also thru my Club
Threadfin Rainbows
Micro Rasboras prob. Merae
Scarlet Badis would not thrive in a normal community tank with fast normal sized small fish. They can be very picky at first. Some will only eat live food at first, tiny food.