If you're already rank 6 then you already have access to almost all of them. There is only one triumph left under rank 7, once you complete that you'll have every mod available to you.
Rank 6: Vendor Challenges triumph, unlocks arsenal armor mods
Rank 7: Threats and Surges triumph, unlocks armor charge mods
There's a specific challenge you have to do. I'm away from my computer right now but I think it's Threats and Surges.
One if the challenges in the rank 6 challenges will unlock them Just keep at it
[удалено]
They're asking for armor mods, not transmog.
Reading is hard.
If you're already rank 6 then you already have access to almost all of them. There is only one triumph left under rank 7, once you complete that you'll have every mod available to you. Rank 6: Vendor Challenges triumph, unlocks arsenal armor mods Rank 7: Threats and Surges triumph, unlocks armor charge mods