Informations about the classes

[PandaCombo]

Hello , my brother wants to joint Final Fantasy as well ... its not 100% sure tho , he asked me if its possible to play a dark knight as a DPS class instead of tank , or the warrior , but i wasnt sure so i thought maybe some one here could help me with that ! i appreciate the answers !!

[Pintsized]

Short answer: no
Longer answer: not viably in groups outside of friends and others willing to let him (and Dungeon Finder in particular will queue him as a tank, period), each class's stats and gear dictate their role, a tank trying to DPS is going to be very sub-par.

[Enkidoh]

As Pintsized said, DRK and MRD/WAR are tank classes, not DPS. Damage dealing is an important part of their repertoire though, they're still tanks through and through.

This page goes into detail about all the classes and Jobs and states what role each class fills.

[Rinari]

As a tank, you can still deal quite a bit of damage, particularly as a Warrior, but Dark Knight is close. Paladin isn't quite is formidable alone (damage-wise), but they can catch up in a raid when all the right buffs are around. You are expected to tank though, which means that keeping the enemy's focus and managing your defenses is your top concern, with damage being secondary. It's a greater responsibility, which is why people shy away from it. In exchange for that extra service to your party, you get much better que times, as tank is generally the most in-need position to fill. People will expect you to know what you're doing though! It's true for everyone, but it's painfully obvious when a tank messes up.

If your friend doesn't want to tank, Dragoon has a similar aesthetic with mail armor and a big sharp weapon.

[Niwashi]

If he's looking at Dark Knight or Warrior because he likes that fierce heavily armored look, but wants to play a damage dealer rather than a tank, would he consider using a spear rather than a sword or axe? Dragoon is about as close as we get to that for damage dealer jobs.