Greater the number of ions released higher the molar conductivity.
[Co(NH3)6]Cl3→[Co(NH3)6]3++3Cl−
also Per mole of the given compounds, [Co(NH3)6]Cl3 gives the highest number of moles of ions i.e, 4 moles.
in case of [CO(NH3)3Cl3] does not ionize
so molar conductivity of [CO(NH3)6Cl3] is greater than [CO(NH3)3Cl3]