Experience at mumbai dropbox H1b stamping!!

[care_candidate]

Can you please share your experience for dropbox H1b stamping? I got specific question if you can answer any of those would be appreciated.

1. How long does it take after submitting the documents to get passport back?
2. I heard if they have doubt, they ask for personal interview or submit more evidence. How does that work?
3. How much time should I allot in Mumbai after documents submission?