Q: How to unlock Efi?

Hi Mohsinalibaig,

If I understand corretly you have setup an EFI pasword and cannot remember what it was. According to the following article you will need to setup a Genius Bar appointment for assistance:

If you lost or forgot your firmware password

Only Apple Retail Stores or Apple Authorized Service Providers can unlock computers protected by a firmware password.

 

If you can't remember the firmware password for your Mac, schedule a service appointment with either an Apple Retail Store or an Apple Authorized Service Provider. If you plan to visit an Apple Retail Store, make a reservation (available only in some countries).

Thank you for using Apple Support Communities.

All the best,

Sterling