Migrating DLP Policies from one tenant to other

There isn’t a built-in export/import mechanism for DLP policies across tenants.
DLP policies contain tenant-bound objects (sensitive info types, locations, conditions, etc.), so they must be recreated in the destination tenant.

The most reliable approach is:

1. Export the policy definitions using Security & Compliance PowerShell
   Get-DlpCompliancePolicy and Get-DlpComplianceRule let you retrieve the configuration, match locations, and extract conditions.
2. Recreate them in the target tenant using the same cmdlets
   (New-DlpCompliancePolicy, New-DlpComplianceRule).
   You’ll need to adjust references to any tenant-specific info types or endpoints.
3. Validate sensitive info types
   If you used custom SITs, they must be exported/imported separately or recreated manually before importing the DLP rules.

Today there is no cross-tenant migration API for DLP, and Microsoft Purview doesn't offer a native copy/clone feature.
PowerShell automation is the cleanest and most predictable path.