[Redmi Note 9S / Note 9 Pro (Indian Model) Guides, ] 81403:
How to unlock & root Redmi 9S & 9 Pro using official tools only - fully working

MOD NOTE: This guide is only for devices with Qualcomm Snapdragon chipsets,

NOT

MediaTek!

This tutorial guides you through unlocking and rooting your Redmi 9 Pro & Redmi 9S (or really any Xiaomi phone that came with MIUI11 and a Snapdragon processor) using official tools with verified sources. This is much more reliable than blindly trusting shady closed-source TWRP mods, which don't fully work or flashing pre-patched boot images, which are not meant for your phone. Note that currently there is no official TWRP for any Android 10 phone.

I have tested this myself on Redmi Note 9S Global, MIUI V11.0.8.0.QJWMIXM. Everything is working as expected, there are no issues with SU and file managers as mentioned in the other thread.

Step 1 - unlocking the bootloader

Skip this section if your phone has its bootloader already unlocked.

1) Insert a valid and mobile data enabled SIM card and sign in or create a Mi Account. This is sadly necessary, as every unlock must be approved by Xiaomi's automated system. It also forces you to wait for a full week with a countdown before unlocking is allowed. This step is necessary only once for the very first time.

2) Download Xiaomi's official unlocking tool. I encourage you to read the linked tutorial specifically the section "Unlocking Bootloader Procedure". tl;dr - you need to enable developer options, go to Settings > Additional settings > Developer options > Mi Unlock Status and apply for an unlock.

3) Reboot to fastboot recovery mode (hold Vol- and Power when powering on the phone) and run the Mi Unlock tool on your Windows PC. After jumping through a few hoops, you should arrive at the following screen saying that you have to wait for 168 hours.

4) Reboot the phone and keep it powered on during the following week. When 168 hours have passed, repeat step 3 and this time it should finally unlock. Note that this erases your data, which is always the case when unlocking bootloader on any Android phone.

Step 2 - installing Magisk and patching your boot image

1) Download the official ROM from here - make sure the model of your phone and the installed firmware EXACTLY match what you're downloading. If they don't, it will most likely NOT work correctly - bootloops, wifi not working etc.

2) Install Magisk Manager (.apk) on your phone from the official Magisk repository.

3) Extract boot.img (about 128MB) from the official ROM zip you downloaded and transfer it to the phone. Click "install" in Magisk Manager and point it to boot.img. This should result in a patched magisk_patched.img (about 15MB - padding was removed), transfer this file to your computer. Ideally to the Mi Unlock folder where fastboot.exe is located.

4) Reboot your phone to fastboot recovery mode. Open a command prompt in the folder of the Mi Unlock tool and run

fastboot flash boot magisk_patched.img

This flashes the patched Magisk-enabled bootloader to your phone.

5) Reboot the phone and that's it! Verify root status in the Magisk Manager app.

Other useful stuff

Here's a link to the official and up-to-date platform tools - ADB and fastboot: https://developer.android.com/studio/releases/platform-tools

This is the custom near-stock Android ROM I ended up using instead of the buggy MIUI ROM: https://xdaforums.com/redmi-note-9-pro/development/gsi-t4105121

There have been developments on TWRP for Android 10, but there is still no official working TWRP for devices that shipped with Android 10 - https://www.androidpolice.com/2020/...h-limited-android-10-support-and-other-fixes/ (as of August 23 2020)