In recent times, Nickel has become a powerful alternative transition metal catalyst for performing cross-coupling reactions due to its low cost and better sustainability. Thus, a sustainable Nicatalyzed C-Se cross coupling has been developed in the presence of catalytic amount of copper iodide as co-catalyst. A wide range of substituted diaryl selenides has been synthesized by this Ni-Cu dual catalyzed C-Se cross coupling. The reaction is following an oxidative addition and reductive elimination pathway where Cu is playing an important role in transmetalation. The mechanism of the reaction was established by several experimental techniques.