Cl2 (g) + Pb(OH)2 (s) + 2 NaOH (aq) → PbO2 (s) + 2 NaCl (aq) + 2 H2O (l)
This is an acid-base reaction (neutralization): Pb(OH)2 is an acid, NaOH is a base.
This is an oxidation-reduction (redox) reaction:
PbII - 2 e- → PbIV (oxidation)
2 Cl0 + 2 e- → 2 Cl-I (reduction)
Pb(OH)2 is a reducing agent, Cl2 is an oxidizing agent.