[Co(NH3)3(H2O)]Cl3
K3[Co(CN)6]
[Co(NH3)2(H2O)]Cl3
[Co(NH3)5Cl]Cl2
Crystal Field Theory -According to this theory, metal and ligand are considered as point charges. This theory deals with electrostatic force of attraction means the talks about the ionic character of M-L bond.As complex K3[Co(CN)6] have CN⁻ ligand which is a strong field ligand amongst the given ligand in other complexes.