To prevent users from saving documents from Microsoft Office applications to their local computer, you can remove the Save As option from the File menu and backstage view.
This can be done by editing the XML files available in the Roaming folder (%AppData%\iManage\Work\Configs):
imWorkRibbon.15.xml
imExcelRibbon.15.xml
imPowerPointRibbon.15.xml
imProjectRibbon.15.xml
imVisioRibbon.15.xml
To remove the Save As menu option, edit these files to add visible="false" after the TabSave parameter as shown:
<tab idMso="TabSave" visible="false">To distribute these modified files to all users, refer to Making configuration files available to users.