Although HTC One received Android 4.4 Kitkat update two days ago, older Flagship phones including HTC One X and One X+ will not received kitkat. They got Android 4.2 Jellybean OTA last year and that was their last update. Recently a news came that AT&T version of One X and X+ may get Kitkat Update by 31st Jan, but yet it is not confirmed.
That is only for the AT&T part, what about the rest of One X devices? Well, they will have run on Jellybean itself. But if we go apart from the official updates, there is a way you can install Kitkat right away on your HTC One X. Here is the stable and fully featured pack Kitkat Custom ROM for One X. The ROM has been tested and works good offering all features of Kitkat on your One X phone.
If you want you can download the ROM from here and follow the installation steps provided in this Guide to get Android 4.4 Kitkat update in next few minutes on your phone. If you have anymore question regarding this ROM or the installation process, we are happy to help, just let us know using the comments box below.