The sum of coordination number and oxidation number of the metal M in the complex $\left[M{\left(en\right)}_2\left(C_2{O}_4\right)\right]Cl$ (where en is ethylenediamine) is

$\left[M{\left(en\right)}_2\left(C_2{O}_4\right)\right]Cl:$
Oxidation number of metal = + 3
Coordination number of metal = 6
$\therefore$Sum of oxidation number and coordination number = 3 + 6 = 9