The first thing to do when deploying Windows updates through SCCM is to deploy the WSUS console on the SCCM server, specifically the site server that will be the Software Update Point (SUP).
To configure SCCM 20012 R2 to deploy updates to the environment first configure the Software Update Point of the Site. In the console under Administration > Site Configuration > Sites > Right click the site and Choose Configure Site Components > Software Update Point.
Configure the settings as you wish.