$(A)$ In octahedral complex: $\left[ M \left( H _{2} O \right)_{6}\right]^{2+}$
$C.F.S.E.$ $=\left(-0.4 \Delta_{0}\right) \times 4+\left(+0.6 \Delta_{0}\right) \times 2+0 \times P$
$(B)$ In tetrahedral complex: $\left[ M \left( H _{2} O \right)_{4}\right]^{2+}$
$C.F.S.E.$ $=\left(-0.6 \Delta_{t}\right) \times 3+\left(+0.4 \Delta_{t}\right) \times 3+0 \times P$
$=-0.6 \Delta_{ t }$
$(i)\, Pt(SCN)_2 · 3PEt_3$
$(ii)\, CoBr · SO_4 · 5NH_3$
$(iii)\, FeCl_3 · 6H_2O$