unable to exclude resource from policy

i wanted to exclude resources from tagging policy (i am unable to create vnet from portal after enforcing below tagging policy to resource group)

{ "mode": "all", "policyRule": { "if": { "not": { "field": "[concat('tags[', parameters('tagName'),']')]", "in": [ "Production", "Development", "Test","UAT", "Staging", "Disaster Recovery" ] } }, "then": { "effect": "deny" } }, "parameters": { "tagName": { "type": "String", "metadata": { "displayName":"Environment", "description": "Name of the tag, such as Environment" } } } }