Resetting Galaxy S 3 to factory default ICS
I found a workaround, Downloaded a firmware from http://www.sammobile.com/firmware/ and updated my galaxy s3 with that using odin. Upon first reboot my phone hangs showing only boot screen with samsung logo for about 2 hours, then I restarted phone in clockworkmod recovery did a wipe data / factory reset and then restarted the phone again, I got the default firmware back. Then connected the phone to pc using kies and upgraded the firmware.