Power on your PC as this process will require a PC, USB cable and Qmobile.
Download Drivers,
Flashtool and
Qmobile stock ROM from the link given
Extract Drivers zip file in a folder
Install Drivers and after installation reboot your PC once.
Now you have to extract Flashtool and Run Flash_tool.exe
Extract Stock ROM rar file in a folder.
Click on Download tab in flashtool and click on Scatter-Loading
Now browse to the ROM folder and select MTxxx_Android_scatter.txt and click Open
Now you have to Click on Download button.
Power off your QMobile S3 and take out its battery for a couple of seconds.
Put the phone’s battery back in and connect your Mobile with PC using USB Cable.
If everything goes well, you’ll see the progress bar and upon completion you’ll see Green Circle.
Now you can Safely Remove your Phone from PC and power it on.
Congratulation, You have successfully Installed.
MT6580 QMobile S3 5.1 ALPS.L1.MP6.V2_RGK6580.WE.L_P2Other Link
QMobile S3-MT6580 GSM_5.1__ALPS.L1.MP6.V2_RGK6580.WE.L_P2 NN