Im using a boolean modifier and the face are correct yet the difference operation not working on it. Im making 2017 and i want to cut the 0 with the shape as u can notice in the image and blend file attach. Plz let me know whats wrong with my model
The blend file provided has already had some Boolean operations applied. Both the 2017 and cut meshes have some doubled vertices and the 0 has overlapping faces.
You should always ensure clean meshes before you attempt Boolean operations.
By deleting 0's upper and lower faces, removing both meshes' doubled vertices ( Mesh > Vertices > Remove Doubles ), then recreating the upper and lower faces, the Boolean operation is applied cleanly. The convex ngon works fine in this particular case.
Don't forget to hide the target Boolean object to see the results.