Coordination Compounds

Possible isomers are
(I) [Pt(NH3)4Cl2]Br2⇒GI=2
(II) [Pt(NH3)4Br2]Cl2⇒GI=2
(III) [Pt(NH3)4BrCl] Br.Cl ⇒ GI. =3
I, II, III are ionisation isomers of given complex and each exhibits two geometrical isomers. Therefore total possible isomers will be 6 .