@Prateek Rana
Thanks for posting your query on Microsoft Q&A.
You can use the following Azure CLI commands to create a script that fits your scenario:
- List all storage account in a subscription - https://learn.microsoft.com/en-us/cli/azure/storage/account?view=azure-cli-latest#az-storage-account-list
- List all containers in each storage account - https://learn.microsoft.com/en-us/cli/azure/storage/container?view=azure-cli-latest#az-storage-container-list
- List immutability policy for each container - https://learn.microsoft.com/en-us/cli/azure/storage/container/immutability-policy?view=azure-cli-latest#az-storage-container-immutability-policy-show