Pin codes from govt sites - PINCODE of india from official sites

 https://dac.indiapost.gov.in/mypincode/home

https://dmsouthwest.delhi.gov.in/std-pin-codes/

https://www.data.gov.in/datasets_webservices/datasets/6818292

https://www.pib.gov.in/PressReleasePage.aspx?PRID=2131707&reg=3&lang=2

Know Your DIGIPIN: https://dac.indiapost.gov.in/mydigipin/home

Know Your PIN Code: https://dac.indiapost.gov.in/mypincode/home

DIGIPIN GitHub Repository: https://github.com/CEPT-VZG/digipin

Georeferenced PIN Code data set: https://www.data.gov.in/catalog/all-india-pincode-boundary-geo-json