Regional update for Samsung Galaxy S4 titled XXUFNC6 Android 4.4.2 KitKat has been released. You can update your Galaxy S4 to XXUFNC6 Android 4.4.2 using this guide [Install XXUFNC6 Android 4.4.2 Official Firmware on Samsung Galaxy S4 i9505].
Here is how you can root Galaxy S4 i9505 on XXUFNC6 Android 4.4.2 KitKat.
Prerequisites to root Galaxy S4 i9505 on XXUFNC6 Android 4.4.2: 
- Create a backup of all important data in your Galaxy device.
- Download and install USB drivers for Samsung Galaxy S4 in your computer.
- Enable USB debugging option by pressing Menu > Settings > Applications. Navigate and tap on Developer Options to ensure that USB Debugging is enabled.
- Ensure that your Samsung Galaxy S4 I9505 carries more than 80% of charge.
- Popular Android 4.4 KitKat based custom ROMs.
Root Galaxy S4 i9505 on XXUFNC6 Android 4.4.2 KitKat official:
Files required: download the Android 4.4.2 XXUFNC6 KitKat root pacage from this link. Also download the Odin3 v3.09 for installation from here. Unzip Odin; and unzip the leaked firmware file inside the same folder as Odin.
- Install Odin on your PC and launch it.
- Switch your Samsung Galaxy S4 off and boot it in Download mode: press and hold Volume Down, Power and Home buttons together.
- Connect your SGS4 via a USB cable; when connected successfully, one of the ID:COM boxes will turn yellow with the COM port number. (In case you don’t get it, try another USB port. If that doesn't help either, then re-install USB drivers).
- From that window, click on PDA and locate the root package to root Galaxy S4 i9505 on XXUFNC6.
- Check the Auto Reboot and F. Reset Time options in ODIN, and click on Start button to initiate the root process.
- When root installation is successfully completed, Galaxy S4 will reboot into Recovery Mode and start flashing the root files; Odin ID:COM will turn green.
- When you see the home screen, unplug your Samsung Galaxy S4 I9505.
