Hello @sandip_surse ,
I believe you are aware that PII refers to Personally Identifiable Information, such as name, email, phone number, address, etc.
If I understand your question correctly, by "unification," you mean stitching data from different sources. In AEP terms, this means defining a field to act as an identity, which allows you to combine data from various sources or link events to a profile.
You don't necessarily need PII data for unification—you can use other unique identifiers, such as CRMID, hashed CRMID, hashed emails, or hashed phone numbers.
If you are using Mobile SDK or Web SDK, you will have the ECID (Experience Cloud ID), which is commonly used for cross-device stitching and is generally available for this purpose.
Kind regards,
Parvesh