I.U.P.A.C name for [Cu(NH3​)4​] [PtCl4​] complex is,  tetraamminecopper(II) tetrachloridoplatinate (II).NH3​ is neutral, making the first complex positively charged overall, so cobalt is in +2 oxidation state. Cl has a -1 charge, making the second complex the anion. As the charge on platinum is -2 so the name ends with -ate followed by the charge in roman letters.