We have enabled the "Rights Management" from Office 365 and also enabled the "Use the IRM service specified in your configuration" in SharePoint administration center. Still the option of "Information Rights Management" is not available in Document Library settings. I have SharePoint tenant administrator rights as well as Site Collection administration rights. There are no custom permission on library as well. I even tried clicking on "Refresh IRM settings" in SharePoint administration center but it did not work.
Am I missing something here?