Which of the following complex compounds has the highest number of geometrical isomers?

Which one of the following complex ions has geometrical isomers?

$STATEMENT-1$: The geometrical isomers of the complex $[M(NH_3)_4Cl_2]$ are optically inactive.
$STATEMENT-2$: Both geometrical isomers of the complex $[M(NH_3)_4Cl_2]$ possess a plane of symmetry.

Which of the following types of isomerism is exhibited by $[Co(NH_3)_5(NO_2)](NO_3)_2$?
$i$. Optical
$ii$. Linkage
$iii$. Ionization
$iv$. Coordination

An octahedral complex of $M^{+3}$ with $NH_3$ and $NO_2^{-}$ ligands has four $M-N$ linkages and two $M-O$ linkages. Which type of isomerism will such a complex exhibit?

$A$ metal complex with a formula $MCl_4 \cdot 3NH_3$ is involved in $sp^3d^2$ hybridisation. It upon reaction with excess of $AgNO_3$ solution gives '$x$' moles of $AgCl$. Consider '$x$' is equal to the number of lone pairs of electron present in the central atom of $BrF_5$. Then the number of geometrical isomers exhibited by the complex is $............$