This is the simplest method. It works as long as you know your current unlock pattern, PIN, or password.
Watch this step-by-step demonstration of the button-based hard reset process:
Approximately 5 minutes.
If the phone asks for a previously used Google or Mi account during setup and you cannot remember the password, you must use official recovery tools. Visit the Google or Xiaomi account recovery web pages on a secondary device to reset your password, then enter the new credentials on your phone.
If the phone hangs on the logo after a reset: How to Hard Reset XIAOMI Redmi S2
If your phone is lost or stolen, you can wipe it remotely using a computer. Go to the mi.com website on a browser. Log in with your Mi Account. . Locate your and select Wipe Data . What to Do After the Hard Reset?
Scroll down and select (or Backup & reset on older MIUI versions). This is the simplest method
How to to the latest version after the reset?
Use this method if:
If prompted, enter your current lock screen PIN, password, or pattern.