Waring: If you follow these steps properly, you will successfully Root your mobile or else you wont. It may leads to Bricking your Phone or other security issues. I'm not Responsible for what happens on your phone. I personally tried this procedure. It works fine for me.
Note: UnRooting is same as Rooting your Device. Instead of update.zip, you will use unroot-update.zip
Steps to UnRoot Galaxy Y
1) Backup your System first (Needed)
2) Now download this file here - Download (unroot-update.zip)
3) Now copy unroot-update.zip file to the SD Card. Do Not put it in any folder. It ain't work.
4) Turn Off your Device and go to Recovery Mode By Pressing and Holding this Key Combination Volume Up + Home Button + Power Button.
5) Once you entered into the Recovery Mode. You will see the Blue Color User Interface where you can't use Touchscreen. Instead use "Volume Up and Volume Down to move Up and Down". And "Home Button to Select". And "Power Button used to go Back"
7) After that select "Apply Update from SDCard" option and choose "unroot-update.zip".
8) Once Patching was successful. You have to Reboot your Phone by select "Reboot System Now".
9) Navigate to Menu, If you find "SuperUser" in your app menu. Click it. It will not open. And all your Root apps wont open or will not work properly. So uninstall all your Root apps. Thats all. You're successfully UnRooted your Galaxy y...
Enjoy and Peace!!!!