$\mathrm{Fe}(26)=3 \mathrm{d}^{6} 4 s^{2}$
$\mathrm{Fe}^{+2}=3 \mathrm{d}^{6}$
In presence of $\mathrm{SFL}\;\;\; 3 \mathrm{d}^{6} \rightarrow \mathrm{t}_{2 \mathrm{g}}^{6} \mathrm{e}_{\mathrm{g}}^{\circ}$
$(i) [pt\ (en)\ Cl_2]$
$(ii)\ [pt (en)_2]\ Cl_2$
$ (iii)\ [pt (en)_2 Cl_2]\ Cl_2$
$(iv)\ [pt (CH_3)_2 Cl_2]$
$(i)\, [Cr(NO_3)_3 (NH_3)_3]$ $(ii)\, K_3[Co(C_2O_4)_3]$
$(iii)\, K_3[CoCl_2(C_2O_4)_2]$ $(iv)\, [CoBrCl(en)_2]$