Is there any way to reset firmware lock

Do NOT buy that MacBook. You can only remove the Firmware Lock with the password that was originally used to set the lock. That MacBook was probably lost or stolen by the original owner. Firmware Locks are a common place with a device is issued by an employer to protect proprietary data in the even the device is lost or stolen.

Axel F.

The official Apple Support might be able to help, if you can present a proof of purchase:

...

If you can't remember your firmware password, schedule an in-person service appointment with an Apple Store or Apple Authorized Service Provider. Bring your Mac to the appointment, and bring your original receipt or invoice as proof of purchase.

...

copied from: Set a firmware password on your Mac - Apple Support