sir your second link is good but not worked on my device so i'm providing a link for those who's device not worked with your tutorials go through this How to Unlock Bootloader of Xiaomi Redmi Note 3 | Officially and Unofficially and if your problem solved with this tutorial then don't forget to like my comment... Enjoy!!
I found actually collected some sites and links that helped me out to unlock my redmi note 3 bootloader and alos i rooted that with this below methods you can check out if you are searching for a perfect explained tutorial. How to Unlock Bootloader of Xiaomi Redmi Note 3 | Officially and Unofficially Root Redmi Note 3 Pro! - XDA Forums - XDA Developers Root Mi Note 3 and install TWRP recovery - Miui - this is for reference... hope this will work on your device by the way have a great day enjoy!!