Identify the incorrect statements from the following I . Tin in + 2...

Correct statments are:-
$I .$ Tin in $+ 2$ state acts as reducing agent while lead in $+ 4$ state acts as strong oxidising agent.
$II .$~Silicon exists as both \left[{SiF}_{6}\right]2 -$but not as \left[{SiCl}_{6}\right]2 -$due to steric hindrance.
$III .$ The hybridisation of carbon in fullerene is ${sp}^{3}$.
$IV .$ Among $Ge, Sn$ and $Pb$ lowest melting point is for~$Pb$.

Thus, $II$~and $IV$& are incorrect.