If `[PtCl_6]^(x-)` follows the Sidgwick rule of stability, what is the oxidation state of Pt and complex ?

Explanation

`[PtCl_6]^(x-)` following Sidgwick rule of stability, thus EAN of Pt is to be equal to the atomic number of nearest inert gas 86(Rn). Let the oxidation state of platinum in `[PtCl_6]^(X-)` complex ion is y
y+6(-1)=-x or y=6-x
86=78-(6-x)+ 2 x 6 = 78-6 + x + 12 , x =2
Oxidation state of platinum forming the complex =6- x =6-2 =+4
oxidation state of the complex =-2.