Hi Konda,
You can modify Airbyte and embed it as a backend in your SaaS. What you cannot do is host Airbyte and sell it as an ELT/ETL tool, sell a product that directly exposes Airbyte's UI or API to your customers, or remove/circumvent license key functionality. On-prem redistribution to clients follows the same rules. Full details
here.
We no longer offer self-managed Enterprise. Features like RBAC, mappings, and multiple workspaces are only on Cloud.
No formal partner program at this time for agencies redistributing Airbyte.