Fallout 4 PC mods which have been made for the PC version of the game will work on Xbox One with the inclusion of Xbox One support for mods, Bethesda have announced during Microsoft’s press conference. The PC mods will be transferable to Fallout 4 on Xbox One at no cost. The mods will only be able to be devleoped and altered on PC though.
However there was no announcement regarding the availability of this feature on Sony’s PS4 so it seems likely that the support of PC mods on console is an Xbox One exclusive.
Source: E3