On this page, you will find the direct link to download Xiaomi Mi 1S Stock Firmware (flash file) from Mediafire. Downloaded file contains the firmware file only.
How to Flash
Step 1: Download and extract the stock firmware on your computer.
Step 2: After extracting you will find the Firmware, and instruction manual.
Step 3: Follow the instruction manual to flash the firmware on your smartphone.
[*] Take a Backup of your personal data before flashing or installing the firmware on your smartphone. As this helps you to recover the personal data whenever any thing wrong happens.