As stated on the Xperia Blog, the Android 5.1.1 Lollipop upgrade for the Sony Xperia C3 has begun rolling out. The build in question is 19.4.A.0.182 and is rolling out for both the single and dual SIM variants.
Fortunately, the upgrade is not being set in one area only, but is available in several regions. If you’re a user who has not received the upgrade yet, you can check to see if it has arrived for your device by accessing System Updates under Settings menu.
For those are not aware, the Xperia C3 comes with a 5.5-inch screen with 720 x 1280 pixel resolution. The Snapdragon 400 chipset powers the device, coupled with 1 gig of RAM and 8GB of built-in memory (expandable via microSD card). It features an 8MP primary camera with LED flash, and a 5MP unit for video chat and selfies. Android 4.4.2 (KitKat) is pre-installed in the phone, which can now be changed with the new upgrade.