Which coins to stack to get good returns? Not talking about a price increase of a coin itself, that's another topic.
If you expect a passive income from a coin, you make a huge mistake. Just saying. Never go for a coin for passive income thing.
Why not?
Passive income means one time you invest and should expect a regular profit from it. But investing in any coins will not give you any assurance that you will always make a profit because there are chances that your coins may go down and sometimes may need wait for few months or year to recover those losses.