H1B Stamping in India before 6 months of current H1 visa expiration

[goutham438]

Hello Everyone,
My current H1B visa with Stamping will expire in August 2019. I applied for extension and i got approval from Aug 2019 to Aug 2022. Next month (I.e in June or July) i am planing to go to India. Can i go for visa stamping on new I-797 copy and get my stamping done till Aug 2022 ?
Am i eligible for drop box ? (My last stamping was in India on Dec 2018)

Any suggestions are helpful...Please advise.

Thanks