koleksiromandroid

This simple step-by-step guide is based on the procedure for Mi3 from @Helgo9 but of course adapted for Redmi 1S. It has been successfully tested on Redmi 1S WCDMA by @imranz with JHCCNBD23.0 and by @matthi with JHCCNBD24.0, furthermore by @adinovic on Redmi 1S CDMA with JHCCNBD23.0. Many thanks go to @sta-s2z.

Prerequisites:

Redmi 1S with stable MIUI ROM
Stock MI-Recovery 2.0.1
update.zip file (attached)
update.zip (1.26 MB)

Summary:
By flashing the attached zip file via recovery the already existing su binary gets the proper permissions and the MIUI version number x.0 is appended to x.0.1 so that the firmware behaves like a developer version and unlocks the stock root.

Root can then be turned on in Security app -> Permissions -> Root permission.

Steps:

Download the file update.zip to your PC (because download via browser on phone often is not working properly)
Connect your Redmi 1S via USB
Copy the file update.zip to the folder ‘Computer\HM 1S\Internal storage’ (root of internal storage)
Disconnect your Redmi 1S properly (‘Safely remove hardware…’)
Boot into Mi-Recovery
Select and confirm ‘English‘ (or Chinese if you are capable to understand)
Select and confirm ‘Install update.zip to System‘, this will take one second
Select and confirm ‘Reboot’
After reboot go to Security app -> Permissions and activate Root permission
Enjoy your rooted Redmi 1S
Caution:

This is a safe process, but I am not responsible for anything bad that happens to your phone
After receiving ROOT the system cannot be upgraded by OTA
But you can upgrade the firmware by flashing the stable version again without wipe, after this the root is gone and you can updgrade to new firmware and most probably execute the root steps from above again
Credits to AndroidFuchs from en.miui.com