Here’s a working method on how you can fix bootloop issue on your Xiaomi Redmi Note 4 MTK phone. Below you’ll find a short, but actually useful tutorial on how to fix bootlooped Redmi Note 4 MTK phone you might want to try.
Solution for bootloop Redmi Note 4 MTK
Turn off your device in bootloop and let it completely drain the battery of your phone.
When it stopped bootlooping, turn it on a few more times until the vibration signal is gone and battery is fully dead.
Press and hold all three buttons for 30-60 seconds for a few times.
Connect the charger (you can try connecting the charger with all three buttons pressed at the same time) for a short period of time.
Now try turning your phone on (with or without connected charger).
If the screen turned on without logo and then turns off, that means the the battery has been reboot.
Now you can turn on your device and enjoy the system startup. Bootloop issue should be fixed by now.