The correct order of CFSE of the following complex ions is $$[\text{Zn}(\text{NH}_3)_4]^{2+}$$, $$[\text{Co}(\text{NH}_3)_6]^{2+}$$, $$[\text{Co}(\text{NH}_3)_6]^{3+}$$, $$[\text{Ir}(\text{NH}_3)_6]^{3+}$$

$$[\text{Ir}(\text{NH}_3)_6]^{3+} > [\text{Co}(\text{NH}_3)_6]^{3+} > [\text{Co}(\text{NH}_3)_6]^{2+} > [\text{Zn}(\text{NH}_3)_4]^{2+}$$

$$[\text{Zn}(\text{NH}_3)_4]^{2+} > [\text{Co}(\text{NH}_3)_6]^{2+} > [\text{Co}(\text{NH}_3)_6]^{3+} > [\text{Ir}(\text{NH}_3)_6]^{3+}$$

$$[\text{Ir}(\text{NH}_3)_6]^{3+} > [\text{Co}(\text{NH}_3)_6]^{3+} > [\text{Zn}(\text{NH}_3)_4]^{2+} > [\text{Co}(\text{NH}_3)_6]^{2+}$$

$$[\text{Co}(\text{NH}_3)_6]^{3+} > [\text{Ir}(\text{NH}_3)_6]^{3+} > [\text{Co}(\text{NH}_3)_6]^{2+} > [\text{Zn}(\text{NH}_3)_4]^{2+}$$