The given complex [Pt(NH₃)₄Cl₂]Br₂ has three ionisation isomers and each of them has two geometrical isomers.

Three ionisation isomers are
(i) [Pt(NH₃)₄Cl₂]Br₂
(ii) [Pt(NH₃)₄ClBr]BrCl
(iii) [Pt(NH₃)₄Br₂]Cl

Ionisation isomers are compounds having same molecular formula but have different counter ions.

Each isomer shown above also possess two more geometrical isomers. Geometrical isomers are the compounds having different arrangement of atoms in space but same molecular formula.

The geometrical isomers are :