For the complex CoCl₃(en)₂NH₃, cobalt is in +3 oxidation state with electron configuration [Ar]3d⁶.
In an octahedral field with strong field ligands (ethylenediamine, ammonia, chloride), Co³⁺ forms a low-spin complex with t2g6eg0 configuration.
The t2g orbitals consist of dxy, dxz, and dyz.
With all 6 electrons filling the three t2g orbitals, the total number of electrons in the t2g orbital set is 6.