1. Find mobile connections on your Aadhar: https://tafcop.sancharsaathi.gov.in/telecomUser/
2. Check if a number/e-mail/bank/UPI is a scammer: https://cybercrime.gov.in/Webform/suspect_search_repository.aspx
3. Check any unkown GST numbers registered on your PAN: https://incometaxindia.gov.in/Pages/annual-information-system.aspx

Fighting Spam

TRAI allows you to activate DND with a SMS which helps blocking

1. Jio/BSNL: START 0 to 1909.
2. Airtel: START 0 to 1909 and complete DND activation by visiting the link shared.
3. Vi: FULLY BLOCK to 1909.

Partial DND:

START 2,3 to 1909.

Calls from 1600/1800 numbers will still come.