How to default the Tax Registration Number on AR invoice based on Legal Reporting Unit (LRU)

Summary

Tax Registration number based on LRU on AR Invoices interfaced from various sources like Subscription . Projects contracts etc.

Content

Hi

Below is the scenario

1 LE with three branches in India, having different GST Registration numbers.  So we have crated one Ledger, One LE with three Legal Reporting Units (1 per branch Chennai, Pune and Bengaluru) and one BU.   Each branch will raise the invoices and the expectation is that the tax registration number should be defaulted based on the Legal Reporting Unit when the invoice is interfaced from various sources like Subscription / Project contracts etc.  Also this data will need to be sent to GST authorities through einvoicing.  Any one has come across such requirements?  Any pointers would be highly appreciated.