H4 Visa dropbox - Mumbai - Eligibility

Hi My wife’s Visa stamping is till Oct 2019 - her I94 is till 2020
I have got H1 extension till 2020

does she (H4) eligible for drop box stamping or she need to go for interview ?

Yes, she would be eligible for Dropbox. You can check out recent H4 Dropbox experience with Appointment.