Six linked default attack

I am playing a Titan, and i am trying to get a six linked default attack, problem is i have no idea of how to do it or if it is even possible, so any help would be greatly apreciated.
I am using 2 handed maces and the ilevel of the mace is not the answer, max level is 84 i bought one, equipped it and it gave me only 5 links.
I am currently level 89 titan.

Thanks in advance.

my best guess is its level locked.
get to 90 and it should be "6L"

Unlocks at lvl 90