Since this is not an Android smartphone, you cannot flash it using ODIN (the Android tool) or install custom ROMs. It runs on a proprietary Samsung OS (TouchWiz UI).
If you still have this device lying in a drawer, flashing the original ODD firmware is the only way to see it boot again. Just remember: patience is key. The download mode is finicky, the USB drivers are stubborn, but when that Samsung logo finally fades into the TouchWiz home screen, nostalgia hits hard. samsung gtc6712 india odd firmware