Tenant registration in Druva for M365 is the process of connecting your Microsoft 365 tenant to Druva. This allows Druva to access and protect your data in M365, including Exchange Online, OneDrive, SharePoint Online, and Teams.

To register your tenant, you will need to provide Druva with the global administrator credentials for your M365 tenant. Druva will then request the required permissions to access and protect your data.

Once your tenant is registered, you can start configuring backup and other protection services for your M365 data.

Currently, it is not possible to add users and enable backups in Druva for Exchange Online and OneDrive from multiple M365 tenants.

If you want to backup the M365 workloads (Exchange Online and OneDrive) for any user, then the user should belong to the same M365 tenant that is already configured in your Druva instance.

M365 backup authentication is based on the single Global M365 admin authentication and permission for an M365 tenant. Due to this, it is possible to use only one M365 tenant with one instance of Druva.

To back up users belonging to a different tenant, you will have to use a different Druva instance.