How to unlock oem in android 5.1 lollipop?

Google introduced a new security feature in Android from Android 5.0 Lollipop onwards. The new feature named as “OEM Unlock” has a meaningful purpose in the device. If you’ve tried rooting your device, unlocking its bootloader, flashing a custom recovery or ROM, you must have seen “OEM Unlock” option to be checked as a requirement for doing any of the aforementioned custom processes. In case