Complex compounds are formed between metal ions and which of the following?

According to Werner's theory of coordination compounds,which of the following statements is correct regarding valencies?

Given below are two statements :
Statement $I$ : $[Co(NH_3)_6]^{3+}$ is a homoleptic complex whereas $[Co(NH_3)_4 Cl_2]^{+}$ is a heteroleptic complex.
Statement $II$ : Complex $[Co(NH_3)_6]^{3+}$ has only one kind of ligands but $[Co(NH_3)_4 Cl_2]^{+}$ has more than one kind of ligands.
In the light of the above statements,choose the correct answer from the options given below.

When $1 \ mol$ of the complex $Co(NH_3)_5Cl_3$ is dissolved in water,it yields $3 \ mol$ of ions. When $1 \ mol$ of the same complex reacts with $2 \ mol$ of $AgNO_3$,it produces $2 \ mol$ of $AgCl_{(s)}$. What is the structure of this complex?

Which of the following is a neutral ligand?

What is the number of moles of ionisable $Cl^{-}$ ions in a coordination complex if it forms $2 \ moles$ of $AgCl$ when treated with silver nitrate solution in excess?