3d Model one side view problem

Hi all, My designer have designed 3d character in Maya. all is fine but a part of cap is looking wired. from up side its not rendering surface, but looks across.
my 3d file is with .fbx extension.
I am using unity version 5.2.2

You need to ensure all the normals of your model are pointing outwards. (Sorry, don’t use Maya, but this should be trivial to do).