How to make a script generated mesh pickable(selectable) in the scene view (Problem with normals)?

I am writing an editor script that generates mesh. Mesh is 2-d planer mesh. Problem is its not getting picked when clicking in the scene view in 2d mode. When I go in 3d mode and try to select the mesh from behind it does gets selected.

I tried to change the vertex normal making them face forward. It didn't work.

Then I tried to change the shader and applied deafault material, and it worked with default unity shader.

So, I think the problem is with my custom shader attached. but its getting picked from behind.

Does anyone know what makes a mesh selectable in the scene view.