Thats quite highly stocked for a 64Ltr tank tbh, the general rule is around 1" of fish per gallon, maybe a little more if the tank has a large filter. The clown loaches will get too big for that tank aswell, they get to around 10" maybe a little bigger when fully grown.
Good advice, it does seem a bit over-stocked, and you have a couple of tank-busters in there, so you will need to get a bigger tank asap if you are going to keep them