Wanted to change the potential on my atlas Ex weapon but says I need lumin fragment emel. Are we even able to find this item or is it part of a future update?

Sounds like the stuff you get from Divide quest, which is EP6 content. JP didn't get to upgrade Atlas EX weapon potentials till well into EP6 so seems like they just included the potential into the game early.

Just give us about two weeks till Ep6 drops. If not by then then several more weeks till Divide quests come out.

They are Luminmech Emmer Fragments from the Japanese server and will be out with Divide quests.