3 NaHS (aq) + NaClO3 (aq) → 3 S (s) + NaCl (aq) + 3 NaOH (aq)
This is an oxidation-reduction (redox) reaction:
3 S-II - 6 e- → 3 S0 (oxidation)
ClV + 6 e- → Cl-I (reduction)
NaHS is a reducing agent, NaClO3 is an oxidizing agent.
This is a precipitation reaction: S is the formed precipitate.