IRM Limitations in SharePoint 2013 On premises.

 

PDF document cannot be in IRM enabled libraries in ADOBE Reader, to make it work we have to rely on third party readers like foxit,nithyo

 

Excel Sheets we cannot open in the browser if these sheets are stored in the SP library where IRM is enabled.

 

We don’t have direct control over IRM permissions in SharePoint 2013,  according to SP permissions given for user on library IRM permissions will work. Means IRM is relied on SP for permissions.   

 

These are true to my investigation from Microsoft Forums and TechNet Articles.