According to a leaked document purportedly originating at Samsung India, the Korean company is going to release Android 4.4 KitKat updates for five smartphones before the end of this month.
These updates have been finalized already, and now the only thing that's left to happen is for the rollouts to start. The information comes from the image you can see above, reportedly via a reputable insider.
That said, you should keep two things in mind: first, that this could just be an image created by someone with Photoshop skills and too much time on her or his hands. Second, that the release time frames here may only apply to devices that were purchased in India.
Of note is that in the case of the Galaxy Grand 2 and the Galaxy Mega 5.8 the model numbers listed indicate we're talking about the dual-SIM versions of these devices (SM-G7102 and GT-I9152, respectively).
It's unclear whether the single-sim variations of these phones will get KitKat before, at the same time, or after the Duos-branded units.