3 moles of metal complex with formula \(\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_3\) gives 3 moles of silver chloride on t…

3 moles of metal complex with formula \(\mathrm{Co}(\mathrm{en})_2 \mathrm{Cl}_3\) gives 3 moles of silver chloride on treatment with excess of silver nitrate. The secondary valency of Co in the complex is _______. (Round off to the nearest integer) [JEE Main 2021, 27 Jul (Shift 2)]