Hi @Paluri Krishnaji (MINDTREE LIMITED),
Thank you for reaching out to Microsoft Q&A forum!
If your endpoint is in France central and you use the geographical endpoint EUR, the data will not move out of the EU. The geographical endpoints for the Translator service in Azure are used to optimize network performance and reduce latency by directing traffic to the nearest data center.
Translator service in Azure does not move data out of data centers. The data is processed and stored within the region where the resource is created. Translator service are typically handled by the data center closest to where the request originated. If there's a data center failure when using the global endpoint, the request may be routed outside of the geography.
I apologize for the requested documentation couldn't found, regarding translation service you can refer to this complete documentation.
I hope this helps! Thanks.