I have a 45 gallon tank and i want to know if my fishes will be good with each other?please help me out?

The danios, tetras, platys should be alright. You could try the gourami's, but supposedly they need brackish water but people have kept them in fresh water so I think it's ok. Depending which pleco you have it could either har your fish or outgrow the tank. The Red tail shark sare aggressive torwards small fish, and within time they will har and kill the small fish when they get older.(I owna red tailed shark) They should only be kept with semi-aggressive fish or others bigger or similar sized fish. So you are better off with the platys, danios, tetras and gourami.