Hi,
You need Content Distribution Monitor tool for that.
With ther release of SEP 12.1 RU6, Content Distribution Monitor tool will be available under Tools folder.
The Content Distribution Monitor tool (SepmMonitor) helps you manage and monitor multiple Group Update Providers (GUPs) in your environment. The tool displays a graphical display of the GUPs' health and content distribution status. You can run the tool on Symantec Endpoint Protection Manager directly or remotely.
To install and use the tool, see the following article and video:
https://support.symantec.com/en_US/article.TECH156558.html
OR
You can download it from here as well: https://www-secure.symantec.com/connect/downloads/new-sep-content-distribution-monitor-gup-health-checking