According to werner theory Primary valency of central atom in Pt(en)2(H2O)2Cl4 Complex is satisfy by fallowing species
Pt(en)2(H2O)2+4
Cl-
Pt+4
en, H2O and Cl-
Cl- satisfy the Primary valency. Hence primary valency Pt(en)2(H2O)2Cl4 Complex is 4