For HK region eligibility certificate, why are they asking for old voter ID before 2002?

Sakala Mission Sakala Mission, Government of Karnataka
Answered on September 14,2021
General documents required to avail this service are listed as below:  

  • An affidavit from the court stating that the applicant is a resident of the Hyderabad –Karnataka region.
  • Driving License.
  • PAN.
  • Birth certificate.
  • Voter ID 
  • Passport.
  • Aadhaar.