Hi Saish Paradkar,
Following our discussion, you are unable to create the Managed Instance in Azure portal with below error message, The resource write operation failed to complete successfully, because it reached terminal provisioning state 'Failed'.
We investigated and got to know that there might be a policy issue which is blocking to create the instance.
In further investigation, got to know that the resource is missing with the policy.
{"code":"InvalidTemplateDeployment","message":"The template deployment failed with multiple errors. Please see details for more information.","details":[{"code":"RequestDisallowedByPolicy","target":"rg","message":"Resource 'rg' was disallowed by policy. Reasons: 'Missing TAG with Owner information. Please add a new Tag with Owner information as shown below:\n\nTag Name: Owner \nTag Value: [Email ID of Owner]'. See error details for policy resource IDs.","additionalInfo":[{"type":"PolicyViolation","info":{"evaluationDetails":{"evaluatedExpressions":[{"result":"True","expressionKind":"Field","expression":"tags[Owner]","path":"tags[Owner]","targetValue":"false","operator":"Exists"}],"reason":"Missing TAG with Owner information. Please add a new Tag with Owner information as shown below:\n\nTag Name: Owner \nTag Value: [Email ID of Owner]"},"policyDefinitionId":"/providers/Microsoft.Authorization/policyDefinitions/871b6d14-10aa-478d-b590-94f262ecfa99","policyDefinitionName":"871b6d14-10aa-478d-b590-94f262ecfa99","policyDefinitionDisplayName":"Require a tag on resources","policyDefinitionVersion":"1.0.1","policyDefinitionEffect":"deny","policyAssignmentId":"/providers/Microsoft.Management/managementGroups/PSL_Project_and_Delivery/providers/Microsoft.Authorization/policyAssignments/5b68a7ed2a844c1a8a19d9d1","policyAssignmentName":"5b68a7ed2a844c1a8a19d9d1","policyAssignmentDisplayName":"Require a tag on resources","policyAssignmentScope":"/providers/Microsoft.Management/managementGroups/PSL_Project_and_Delivery","policyAssignmentParameters":{"tagName":"Owner"},"policyExemptionIds":[],"policyEnrollmentIds":[]}}]}]}
Recommended you to try to delete the policy assignment and to create the SQL managed instance.
Successfully, managed instance is created.
Please refer the below document about the SQL MI,