@Sangram Jena - Welcome to Microsoft Q&A and thanks for reaching out to us.
To unlock the Immutable vault, you can follow the below steps:
- Go to the Recovery Services vault, go to Properties > Immutable vault, and then select Settings.
- On Immutable vault, uncheck the Lock immutability checkbox to disable the lock.
- Select Apply to save the changes.
Once you have unlocked the Immutable vault, you can follow the steps mentioned in the document to delete the vault.
Please note that you cannot delete a Recovery Services vault if there are any backup items in soft deleted state in the vault. The soft deleted items are permanently deleted after 14 days of the delete operation. So once the backup items are permanently deleted and there is no item in soft deleted state left in the vault, then try to delete the vault.
Hope this helps. and please feel free to reach out if you have any further questions.
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