The best way that I've found to export from C4d is to group your animation then bake as alembic, then export as an fbx file. After that follow the below procedure:
-import your animated object to your project
-add an animation controller in project window
-double click on the animation controller
-create empty state in the animator window, which should connect to the entry node
-click on the empty state, you just created and connect the motion slot to your imported animation
-add your imported animated object to your scene
-click on your imported animated object in the Hierarchy and add an animator component if there isn't one
-connect that animator component to the animation controller
Check out this link for a video walk through of the process for adding an animation controller.
In addition to the Tobias's explanation, the following article may be helpful to export an animation of Cinema4D.
How to I export an animation from Cinema 4d and import it into Unity for a STYLY scene?