@sachin sharma Thank you for reaching out to us!
You can use RMAN to back up your on-premises Oracle databases to Azure. Doc reference: https://learn.microsoft.com/en-us/azure/architecture/databases/idea/migrate-oracle-azure-iaas#do-migration-activities or you can use Azure Migrate to migrate the VM as a whole to Azure. Refer to this article - https://learn.microsoft.com/en-us/azure/architecture/databases/idea/migrate-oracle-azure-iaas
Hope this helps. Please reply if you have any questions.