The ion which is not tetrahedral in shape :

The element ${\mathrm{ICl}}_4^{-}$

2 lone pairs of electrons and 4 bond pairs of electrons are present. ${\mathrm{sp}}^3{\mathrm{d}}^2$ hybridization occurs on the central iodine atom. The actual geometry is square planar as opposed to the anticipated octahedral shape. 

${\mathrm{BF}}_4^{-},{ \mathrm{NH}}_4^{+}$ and ${\mathrm{XeO}}_4$ are shaped like tetrahedrons.