@Mahadev, Rakesh [HAEA] Thanks for reaching here! As per official document- https://learn.microsoft.com/en-us/azure/search/search-reliability#back-up-and-restore-alternatives
A business continuity strategy for the data layer usually includes a restore-from-backup step. Because Azure AI Search isn't a primary data storage solution, Microsoft doesn't provide a formal mechanism for self-service backup and restore.
However, you can use the index-backup-restore sample code in this Azure AI Search .NET sample repo to back up your index definition and snapshot to a series of JSON files, and then use these files to restore the index, if needed. This tool can also move indexes between service tiers.
Refer to Back up and restore an Azure AI Search index
Hope this helps! Let us know if further query happy to assist.