The hybridization observed in the $[PtCl_6]^{2-}$ ion is .......

$A$ list of species having the formula $XZ_4$ is given below.
$XeF_4, SF_4, SiF_4, BF_4^-, BrF_4^-, [Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [CoCl_4]^{2-}$ and $[PtCl_4]^{2-}$.
Defining shape on the basis of the location of $X$ and $Z$ atoms,the total number of species having a square planar shape is

Which of the following statements are true about $[CoF_6]^{3-}$ ion?
$I$. The complex has octahedral geometry.
$II$. Coordination number of $Co$ is $3$ and oxidation state is $+6$.
$III$. The complex is $sp^3d^2$ hybridised.
$IV$. It is a high spin complex.

Which statement is incorrect regarding the complex $[Cr(NH_3)_6]Cl_3$?

In aqueous solution,$[Co(H_2O)_6]^{2+} (X)$ reacts with molecular oxygen in the presence of excess liquor $NH_3$ to give a new complex $Y$. The number of unpaired electrons in $X$ and $Y$ are,respectively:

Assertion : $[FeF_6]^{3-}$ is a low spin complex.
Reason : Low spin complexes have a lesser number of unpaired electrons.