Is this android? If so there should be a option there on the unlock screen somewhere to reset the lock pattern using your email login attached to that device.
If there is no option to do this then you may need to completely "factory reset" the device, this will delete everything on it though!!!
Factory data reset in Recovery mode
If your Android One is on, turn it off.
Press and hold the Volume up button and the Power button at the same time until the device turns on.
Press the Volume down button to select "Recovery mode." If you need to navigate to the "Recovery mode" option, use the Volume up button to move the arrow and the Volume down button to select it.
You’ll see an image of an Android robot with a red exclamation mark and the words "No command."
While holding down the Power button, press the Volume up button and release it.
Use the volume buttons to scroll to "wipe data/factory reset" and press the Power button to select it.
Choose to erase all user data. This may vary by device. For example:
Scroll down to "Yes - erase all user data" and press the Power button to select it.
When asked to "Wipe all user data?", select Yes.
Your Android One device will erase all of your data and restart with its factory settings.
https://support.google.com/android-one/answer/6088915?hl=en