It is very simple to root samsung galaxy y duos just download the file (update.zip) given below and place it in SD card (not in any folder) then turn off the phone after that press 3 buttons together POWER BUTTON + MENU BUTTON + VOLUME UP BUTTON then device will boot in recovery mode then select install update from sdcard --> then select update.zip from sdcard
your device will be rooted!
File download from here :---