As per BTRC action plan, all mobile phone users are required to re-verify their SIMs through biometric verification system. All un-verified SIMs will get closed after 30 April 2016.
To know if your SIM is verified or not, follow below procedure to make sure:
Check GrameenPhone SIM is biometric verified or not
write Reg and send SMS to 4949 (Free)
Check Banglalink SIM is biometric verified or not
dial *1600*1# (Free)
Check Robi SIM is biometric verified or not
dial *1600*1# (Free)
Check Airtel SIM is biometric verified or not
dial *121*444# (Free)