To flash and restore your Xiaomi Redmi Note 7S to it’s factory default state, you need to flash the official fastboot ROM- like the one on this page. Aside restoring your device to default state, you can upgrade/update the phone version, move from Beta to Stable ROM (vice versa), or even un-brick your bricked phone. To state the obvious (or is it?), if you flash this Fastboot ROM on a rooted device, it will overwrite all existing modified system files to replace with factory default software.
So, ensure that all important data on the phone (contacts, messages, app data, etc.) is safe by backing all up to a safe platform or cloud storage, because you might loose ALL data after flashing. Also, charge the phone to at least 30% battery capacity. It is wrong to interrupt the flashing process for any whatsoever.
Now that you’re up to speed, download the Fastboot ROM from the link(s) below and follow the recommended flashing instructions immediately after the download options. Do not hesitate to report any broken links detected. Ensure to download the exact ROM for your region/country. If you need help, post in comments section.
Download Xiaomi Redmi Note 7S official Fastboot ROM
Important! Always backup existing firmware before flashing any firmware.
How to flash Xiaomi firmware
After downloading the firmware from above link, get a functional USB cable, then follow the instructions via this link to learn how to flash Xiaomi fastboot and recovery firmware.
If you have any questions or other contribution please post in comments section for assistance.