It’s hard to be sure because you didn’t pack the textures into the .blend, but from the names of the textures it looks like you’re using a Roughness map for your Normal Map node.
This is a big no no. Normal Mapping needs specific Normal Map textures to function correctly. You can tell Normal Map textures because they are usually a light blue-ish color with hints of red and purple and teal.
If you haven’t got the correct normal map texture for you object, you can try using the Roughness as a bump map instead. In that case, simply replace the Normal Map node with a Bump node, and connect the texture to the Height input.