H4 Interview done - No Stamping No Rejection due to extension, Dropbox?

USA H4 Visa
1

Hi,
Please guide me in this case…

Now I (H1) am applicant in US. I tried H4 stamping (first time stamping) on Jul-19 that point of time my visa valid mid of Aug-19. In Chennai consulate My family did bio metrics no issues.
Next day interview the consulate officer said they cannot approve the visa since my visa validity less than a month and extension is in-progress and in addition to that the bio metrics and visa interview valid for next 1 year my family (H4) no need to attend the interview just submit the documents and passport for stamping after received the extension approval. Now my extension approved for next 2 years

My query is
Is my family eligible for drop box in that case?
Where we need to submit documents for stamping? Bio metrics and interview attended in Chennai, Is that possible to submit Bangalore as my family in Bangalore?
If no need of interview should need to book fill DS160 and an appointment?

2

Yes, they would be eligible for dropbox now.
You can submit the documents in Bangalore. Yes, you will get that option to dropoff documents in Bangalore, if you select Chennai Consulate.
You need to do DS-160 and then you will be asked to book dropbox appointment. This is as per new rules. Check Dropbox Mandatory now in India for US Visa Stamping