1. Download Update.zip file below attachment and copy the Update.zip file in to the root of the SD Card.
2. Switch off your mobile phone
3. After the complete phone switched off, go to recovery mode. For this recovery mode, hold the power, volume up and the home buttons simultaneously.
4. Now can navigate through recovery mode only with the volume up and down buttons. Select Update.zip and the root will be applied on your Galaxy Y.
5. Reboot your phone and it's rooted!! You can check for an application named "Super User" to check whether your phone is rooted or not.
Note:- It is working in my mobile 100% without any problem. I am not responsible for, if it is not working, damage your mobile and or any other issues.