Hello @Siva ,
Thank you for reaching out to the Microsoft Q&A platform. Happy to answer your question.
I understand you are looking for an approach to restore all the VMs at a resource group level probably to make the recovery process easier. However, there is no possible way to perform restore from resource group level using PowerShell or Portal in Azure backup.
You can do parallel restores of VMs using both Portal and PowerShell in case you get into a situation where you will have to restore all the VMs in a RG.
Here is a link to the azure backup documentation with the list of restore options, in case you want to explore other options backup-azure-arm-restore-vms
Hope this helps!
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