The d-electron configuration of $\left[\mathrm{Ru}{\left(\mathrm{en}\right)}_3\right]{\mathrm{Cl}}_2$ and$\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right] {\mathrm{Cl}}_2$ respectively are:

Fe and Ru belong to the same group and their oxidation states in the given complexes are  ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Ru}}^{2+}$ respectively.

Both ${\mathrm{Fe}}^{2+}$and ${\mathrm{Ru}}^{2+}$ have d⁶configuration. In $\left[\mathrm{Ru}{\left(\mathrm{en}\right)}_3\right]{\mathrm{Cl}}_2,$the electronic arrangement becomes ${\mathrm{t}}_{2\mathrm{g}}^6{\mathrm{eg}}^0$. 

In  ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+},$the electronic arrangement becomes ${\mathrm{t}}_{2\mathrm{g}}^4{\mathrm{eg}}^2$ because ${\mathrm{H}}_2\mathrm{O}$ is weak ligand.