Yes, it is "ver 2.4" If you're from Karachi I can tell you about the computer shop I got it from, he is very good friend of mine.
I also asked about using Wimax dongle with 3G/4G routers on different forums but nobody could answer it because 3G and Wimax are different technologies.
But now I think I know that Wateen Wimax USB dongle will "not" work with this TP-Link router because when I was setting up this router it asked the country. Upon selecting Pakistan it automatically gave 2 options to choose from (worldcall and PTCL) there was no Wateen in the list.
It cannot be configured to use it with Wateen Wimax