All ligands are .....

Which of the following is a basic ligand?

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.

How many ions are present in $K_4[Fe(CN)_6]$?

On treatment of $10 \ mL$ of $1 \ M$ solution of the complex $CrCl_3 \cdot 6H_2O$ with excess of $AgNO_3$,$4.305 \ g$ of $AgCl$ was obtained. The complex is

If $N$ is bonded to the central metal atom in $SCN^-$,what will be the name of this ligand?