The first ranged weapon for Dancer is the Rogetsurin, a level 15 Chakram-type (returning) weapon dropped 100% from Haty and Bendigeit Vran in Konschtat Highlands. These NMs only spawn at night during or very close to Full Moon (Haty) or New Moon (Benigeit Vran).
To be honest these are well over-priced. Since chakrams aren't exactly known for doing high damage, you're better of just getting a Rogetsurin -- you can use it five levels earlier, anyways. THFs can opt for boomerangs instead, or should really just do marksmanship instead.