Can i mix like tetra's and little stuff like that with rope fish and things like that.?

i have 8 neon tetra's 4 white cloud danios and 2 zebra danios. i also have a common pleco. and a cory cat. i kno ur suposed to have like 3 or 4 cory cats so im gona go buy more tommorrow. but can get some rope fish or freshwater eels or anything like that. or the long loaches. i also have live plants can i do that?