when i render my scene while using normal maps, some parts are completely black and renders correctly on the wrong side. i have checked my normals but they are pointing in the right direction.
And what do you expect the community to see here? No wireframe to see the faces, no normal map image and your image seems to use some transparent part ??
And what does
some parts are completely black and renders correctly on the wrong side
mean? Sorry but if you expect some help…
and the completely black faces seems to be rendering right on the wrong side
my .blend: https://www.mediafire.com/file/5s3vdlckjl79sds/blend.zip/file
and the completely black faces seems to be rendering right on the wrong side
Except from the first image i can see your tiles 
! So what’s the problem 
?
It’s a very bad habit to talk about a problem, show some screenshots and send a file with five textures consuming 7.7MB and the screen shot of one setting shows only 2 used. And then the textures aren’t set up like in the screen shot but even nowhere connected. So nobody can tell you what your problem is while you are using a different file !!! 
And be the way your normal map setting is wrong.
… Looks fine here:
