The square planar complex of the type [Mabcd]n±, where all four ligands are different, has 3 geometrical isomers. But if one of the ligands is ambidentate, then 2×3=6 geometrical isomers are possible. But if two ligands are ambidentate, then 4×3=12 geometrical isomers are possible. In the given example, NO2−and SCN−are ambidentate ligands.