Passport has expired. How long it takes for a new Passport?? Please help.

[Sid0320]

I'm living in the US on H1B. I need to go to India but I'm not getting any visa interview dates at the embassy before May/June. My Passport expires in Oct. and I need to get a new Passport due to the 6 month clause.

If I apply for a new passport at the Indian Embassy in DC/Chicago etc, with all the correct documents, what is the shortest length of time the new passport will come in to me????????

Please help.