From the U.S. Embassy & Consulates in India website:
The Department of State has authorized consular officers to waive the in-person interview requirement for certain categories of visa applicants through 31 December 2022. This new authorization applies to travelers applying for F, H-1, H-3, H-4, non-blanket L, M, O, P, Q, and academic J visas who were previously issued any type of visa, if they are applying for a visa in their country of nationality or residence. This authorization does not apply to applicants who have a previous refusal that was not subsequently waived or overcome. Adjudicating consular officers may request an in-person interview if additional information is required from applicants.
Applicants renewing any visa within 48 months of expiration also continue to be eligible for interview waiver.
In the coming days, the U.S. Embassy and Consulates in India will release more than 20,000 additional interview waiver (dropbox) appointments for Spring 2022 to allow qualified applicants to make use of the new interview waiver authority. Due to reduced staffing and numerous pandemic-related disruptions to our operations since March 2020, appointment demand is high across all visa categories and wait times may be lengthy for most routine nonimmigrant visa appointments at the U.S. Embassy New Delhi and the consulates in Chennai, Hyderabad, Kolkata, and Mumbai.