Custom kernels, Android based OS, and add on Xpose modules, etc.
First you need to unlock your device using TWRP, or equivalent.. Follow the steps for unlocking Redmi 3S A.K.A Land; but remember do it on your own risk and also your warranty will void.
Install ADB drivers from ADB folder (run as adminstrator) then install Xiaomi PC Suite and on your mobile device: Go to Settings ==>> About phone ==>> tap x10 times to unlock developer option. In Developer Options ==>> activate USB Debugging & OEM Unlock and boot your device into downloading mode by pressing / holding power + volume down, when boot screen appear then jack your device in PC via USB.
Open CMD and flash TWRP.img file into ROM.
then Voila again boot into recovery mode pressing / hold volume up + down + power button.
then flash your zips file directly from TWRP bootloader.