NIE request, results time frame

I am in need of help to get insight view on NIE results time frame. I have applied for NIE on July 6th and awaiting for results, I got my last stamping done in London( US Embassy) and all previous stamping were made in Mumbai. I got acknowledgment same day from Mumbai NIE. I need approval to travel I have stamped Visa till 2022.

Please help and guide on my request…

Can anyone please help and guide on my request. I had applied for NIE to Mumbai US consulate on July 6th and waiting for results.