How ammonium chloride is acting as an oxidising agent and reducing agent

Dear student,

The substances that are reduced (provide oxygen or remove hydrogen) in course of the reaction are called oxidizing agents. These substances oxidize other chemicals in the reaction and are reduced in the process. On the other hand, the substances that are oxidized (remove oxygen or provide hydrogen) are called reducing agents.
In case of ammonium chloride if we saw its reactions as:
$N{H}_{4}Cl + NaOH \to N{H}_{3 }+ NaCl + H_{2}O$
In this reaction the oxidation state of nitrogen remains same. 
2NH₄Cl + Ca(OH)₂ -> CaCl₂ + 2NH₃ + 2H₂O
Therefore, we can see it do not act as reducing as well as oxidising agent. The oxidation state of nitrogen does not change.

Regards