Back at the beginning of December we reported a screenshot taken from the PS Store indicating that Nuk3town would become available to everyone on January 26th.
From December article:
Sony have updated the Nuk3townBonus Map item in the PlayStation store to include a new release date of January 26th 2016. The item no longer mentions that it was a pre-order exclusive – so expect everyone to be causing carnage on this map soon.
January 26th has been and gone with still no sign of the map being available. Activision has confirmed through Reddit that this was user error and that there is no plans on releasing the map to everyone stating it was a pre-order exclusive only.
If you did not pre-order Black Ops 3 it is unlikely you will ever see Nuk3town come your way.