hi,
well my religion system isnt like the regular one, each civ can found up to 2 religions, also some civs, cant even convert to some religions, its hard coded, cause i wanted to give religion some spice while adding to the difference between nations.
so, you can see druidism, cause yor civ probably cant learn it.
in the civilopedia you can see what religion is foundable to each civ along with the forbidden religions that you cant convert into.