After this 12 April 2015 no dates are going to be revised or extended. All those users who have not verified sims biometrically will not be able to use sims after 12 April 2015.
More than 75 million issued sims have been verified biometrically out of more than 120 million sims. All companies are running campaigns so that their users go through biometric verification.
After 12 April 2015 sims will be issued by new method, no details yet available, so that users are already biometrically verified. The final date for biometric sim verification is now 12 April 2015