Update Manager 6.7 is compatible only with vCenter Server 6.7 and its components.
An Update Manager server that runs on Windows is only compatible with the vCenter Server that runs on Windows and the vSphere Web Client.
The vCenter Server Appliance is packed with the Update Manager server, and after deployment runs Update Manager as a service. The vCenter Server Appliance supports Update Manager client interfaces in both the vSphere Client and the vSphere Web Client.
There are differences in the Update Manager user interface between the vSphere Client and the vSphere Web Client. For example, in the vSphere Client you are unable to change Update Manager configuration settings, or change default remediation options in the remediation wizard, or remediate VMs. For such operations, use the vSphere Web Client.