Out of the following complex compounds, which of the compound will be having the minimum conductance in solution?

Electrical conductance depends on the number of ions produced in the solution.$[\text{Co}({\text{NH}}_3{)}_3{\text{Cl}}_3]$ is a neutral complex and does not ionize. It produces $0$ ions.$[\text{Co}({\text{NH}}_3{)}_4{\text{Cl}}_2]\text{Cl}$ produces $2$ ions ($1$ complex cation + $1{\text{Cl}}^{-}$).$[\text{Co}({\text{NH}}_3{)}_6]{\text{Cl}}_3$ produces $4$ ions ($1$ complex cation + $3{\text{Cl}}^{-}$).$[\text{Co}({\text{NH}}_3{)}_5\text{Cl}]{\text{Cl}}_2$ produces $3$ ions ($1$ complex cation + $2{\text{Cl}}^{-}$).Since $[\text{Co}({\text{NH}}_3{)}_3{\text{Cl}}_3]$ does not produce ions, it will have the minimum conductance.