Whips in final fantasy games have typically been usable form the back row, which makes it a ranged weapon.

But for implementation in FF14, I'd expect it to be a bit of a hybrid. A melee weapon, but with a 6-yalm range instead of the standard 3-yalm range. It would suit a new Scouting job pretty well, considering Ninja is already a melee/ranged hybrid with it's use of Aiming accessories and several ranged attacks via Ninjutsu.