You have two kribensis there.
I maybe wrong though lol.
25g tank for all the people in the US.
With the kribs, Betta (fighter fish) and the tetars your getting closed to stocked IMO
. I'm not 100% sure on the minimum tank size for the kribs but I'm sure someone else will chime in. I'd up the school of tetras back up to 6. You've got room for maye one bottom feeder like a bristlenose pleco (not a common!). I wouldn't do a school of cories or loaches because the kribs have claimed the lower regions as their territory and the tanks not big enough to allow more.