Most probably this is one of the working methods on how to bypass and use Redmi Note 4 MTK (Nikel) with blocked Mi-Account.
If you decide to try the following method, pay attention that you’re responsible for any possible issues.
You’ll need to download and install the modded MIUI ROM version without any Mi services. This version will work with the locked bootloader.
In case you’ve got your own working solution, please share one in the comments below!