Official Samsung Galaxy S3 Neo update is now available from download. This update will upgrade your android device to android 4.4.4 kitkat. This phone was launched in april with android 4.3 onboard but has now been upgraded to Android 4.4.4 kitkat. 
This S3 Neo comes with Snapdragon 400 compared to Exynos in the non Neo S3 version. This new update brings more fluid interface, transparent status bar and available for download via KIES and OTA. You can also download it as full ROM from link given below.
You can root S3 Neo on android 4.4.4 by following instructions given here. Use ODIN to flash this ROM.