The reaction between Ammonium chloride and Barium hydroxide is an endothermic reaction.
Ba(OH)2 +2NH4Cl → BaCl2 + 2NH3 +2H2O
Ammonium Chloride is slightly acidic and Barium Hydroxide very basic so will get an acid-base reaction.
This reaction is used to recover ammonia in the preparation of sodium carbonate from NaCl.