Which among the following complexes is heteroleptic and cationic in nature?

The coordination number of cobalt in the complex $[Co(en)_2Br_2]Cl_2$ is

The sum of the oxidation state (magnitude) and the coordination number of cobalt in $Na[Co(bpy)Cl_4]$ is $.......$ (Given $bpy = 2,2'-bipyridine$)

Consider the following statements according to Werner's theory:
$(a)$ Ligands are connected to the metal ions by coordinate bonds.
$(b)$ Secondary valencies have directional properties.
$(c)$ Secondary valencies are non-ionisable.
Of these statements:

One mole of the complex compound $Co(NH_3)_5Cl_3$ gives $3$ moles of ions on dissolution in water. One mole of the same complex reacts with two moles of $AgNO_3$ solution to yield two moles of $AgCl_{(s)}$. The structure of the complex is

Which of the following species is $NOT$ a monodentate ligand?