There is no C4D shader. You can change the composition settings to use the C4D rendering engine or you can import a C4D file and drag it to the timeline. That workflow will add Cineform to your C4D layer.
If you do not have a layer set to 3D the render options (Classic or C4D) will not show up in the top right-hand corner of the Composition panel.
I don't know what you are looking for or trying to do, but there is no such thing as a C4D shader in After Effects.