Samsung is pushing Android 4.3 update for Galaxy S4 users in India. Samsung started pushing updates to Galaxy S4 devices in Europe last week and now they are doing it in India, the update will reach all regions in the next few weeks. This update is for GT-I9500 devices, which has Exynos Octa Core chip inside.
The firmware update for Galaxy S4 includes new features and support for Galaxy Gear along with improvements and bug fixes. Samsung is rolling the update in phases. so don’t worry if you haven’t seen the update. Alternatively you can go to Settings > About Phone and Software Update to check if the update is available to you. The update is available as OTA update, and also through Samsung Kies.
Apart from improved performance the update brings support for Knox, TRIM, Reading mode, Galaxy Gear and security enhancements.