As you well know, Samsung released the official Android 4.3 update for Galaxy S4
a few days ago in Germany. Samsung has the habit of releasing one update first, and then other countries will follow it.
Android 4.3 was released for both GT-I9500 and GT-I9505 versions, meaning the non-LTE Exynos version and the LTE Qualcomm one as well as for the Korean Galaxy S4 SHV E300K. Here are the countries that received Android 4.3 so far:
For the GT-I9505
: Malaysia, Singapore, Singapore (SingTel), Singapore (StarHub), Philippines (Smart), Philippines, Philippines (Sun), Philippines (Globe), Singapore, Germany.
For the GT-I9500:
United Arab Emirates, India, Indonesia, Vietnam, Russia.
Both Galaxy S4 models have received firmware XXUEMJ5. The Korean Galaxy S4 SHV-E300K
has received firmware E300KKKUEMJA. For the countries that have received the update, the installation can be done with Samsung Kies, or if an OTA appeared on the screen you can use this method as well.
Other countries will receive the update in the following days. Make sure you have a WiFi connection and you check for OTA's regularly. Keep an eye on SamsungUpdate to see when your country receives the update, so you can install it with Samsung Kies.