There are several issues now in this thread as others have mentioned. First, most of the fish being mentioned require considerably more space than this tank provides.
All tetras (as well as rasboras, danios, barbs, most catfish, all loaches, and some others) are shoaling fish so they need a decent-sized group of the species. A group of around 10 is preferable for most of them. Swimming activity levels vary with the species, so some cold manage here, others (like the rummynose tetra mentioned) could not.
You cannot mix cichlid species especially in this small a tank. Assuming the dimensions are in inches, my earlier advice on the rams holds. But there is a temperature issue with rams, they must have it warmer than most of the other fish can tolerate long-term, so suitable tankmates is not easy to sort out.
Small tanks are best suited to what are termed "nano" fish, which are fish that are very small at maturity, less than an inch. We also need to know water parameters for your source (presumably tap) water, namely the GH (general hardness) and pH. Fish have preferences here, and small fish are more sensitive.