@Prajith K , Thank you again for bringing this issue related to "Resource health alert" to our attention. Here are some additional details that should help you:
1. In Azure portal, for Alert rule being created from “Service Health” --> “Resource Health” --> “+ Add resource health alert”, the tags cannot be added as of now. However, our product group is working on it, and it should be available in the next few weeks.
2. If you are planning to create "Resource Health Alert Rule" for a particular resource, you may use the Alert option available in that resource properties. For example, for a particular VM, it can be created using the Alerts options as shown below, where tags can be added:
3. If you would like to enable it for a set of resources OR all the resources, you can use the ARM template deployment method, which supports tags. Please see this link for details and this link for a sample template.
Please let me know if you have any questions. 2: https://learn.microsoft.com/en-us/azure/templates/microsoft.insights/activitylogalerts?pivots=deployment-language-arm-template