Here follows a tutorial on how to root your Galaxy S3 to have root permissions. Having root access is like having admin rights on your computer which allows you to modify files and install Apps which you normally don’t have permission for. Keep in mind that rooting your phone voids warranty.
What you will need –
Steps to Root Galaxy S3 –
1, Download both files , and extract to a specified folder using Winrar .
2, after extracting the Kernel file , you will have a .tar file in the folder .
3, Now turn off your device and get your phone into reovery mode ( You can do that by pressing Volume down + Power button simultaneiously and volume up button when asked .
4, Now connect your device with your P.C via data cable and open Odin .
5, in Odin select pda and then select the .tar file you extracted in step1 and 2 .
6, Click on Start the the process will be started .
7, Once you are done , turn on your device and from settings > applications > development enable usb debugging .
8, Download the sgs3-root-install-zip which contaun SuperSU , and extract it .
9, With adb running ( Android Debug Bridge ) , double click on install.bat .