Hello @Muddu Venkata Narasimha Murthy ,
If you have enabled Network Watcher for a region, you should be able to see topology for the resource group deployed in that region. I checked in my lab and I am able to view topology for all the enabled region RGs without any issues. So, your case needs further investigation.
Also, Opting-out of Network Watcher automatic enablement is a permanent change. Once you opt-out you cannot opt-in without contacting support.
Please refer : https://video2.skills-academy.com/en-us/azure/network-watcher/network-watcher-create#opt-out-of-network-watcher-automatic-enablement
Hence, if you have a support plan, I request you to file a support ticket, else please do let us know, we will try and help you get a one-time free technical support. In this case, could you send an email to azcommunity@microsoft.com referencing this thread as well as your subscription ID. Please mention "ATTN gishar" in the subject field.
Thank you for your cooperation on this matter and we look forward to your reply.
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