MS defined a major bunch of lp packs for TP. If your local version is not included you must use the en-us version instead. RTM will give you all language versions you need, so be patient
fg.v4.download.windowsupdate.com/c/msdownload/update/software/updt/2015/04/microsoft-windows-languagefeatures-basic-hu-hu-package_dbb0e985ddd915fbaa6a3b42e26a352fce4236c0.cab Hungary fg.v4.download.windowsupdate.com/d/msdownload/update/software/updt/2015/04/microsoft-windows-languagefeatures-ocr-hu-hu-package_dd3ada939a31da4d0bf57917ca7c7692d3bad389.cab Hungary
I also know the "but" which is so temporary that it can be overwritten by tomorrow, though. It is quite useless to engage in a huge work that only lasts for some days ... lol
like faikee said: learn the way RTM numerology is made at Redmond. A 10256-16384 XXXXXX-XXXX could be a possible RTM version but is only speculation
I've installed this build, clean install, in a VHDX and now I've noticed that Realtek sound and AMD video drivers wasn't installed
result is: 646,5625 ... so NO ...lol if considered as RTM. Any other builds are possible until the build machine comes to the final stage