In homoleptic complex, only one type of ligand is present.
In heteroleptic complex, more than one type of ligands are present.
(i) K4[Fe(CN)6] and (iii) K2[Zn(OH)4] are homoleptic complexes.
(ii) [Co(NH3)5(CO3)]Cl and (iv) [Pt(NH3)2Cl(NO2)] are heteroleptic complexes.