Consider the following complex ions
 $$\begin{gathered} P={\left[Fe{F}_6\right]}^{3-} \\ Q={\left[V{\left(H_{2}O\right)}_6\right]}^{2+} \\ R={\left[Fe{\left(H_{2}O\right)}_6\right]}^{2+} \end{gathered}$$
The correct order of the complex ions, according to their spin only magnetic moment values in (B.M) is 

 ${\left[\begin{array}{cc}Fe& Fi\end{array}\right]}^{-3}:F{e}^{+3}\left(Ar\right)3d^5$
 
 $F:$ Weak field ligand             
No.of unpaired  $C^{-}=5$
 $$\begin{gathered} \mu =\sqrt{55+2} \\ \mu =\sqrt{35}B.M \\ {\left[V{\left(H_{2}C\right)}_6\right]}^{+2} :V^{+2} :3d^3 \end{gathered}$$

No.of unpaired  $e^{-}=3$
 $$\begin{gathered} \mu =\sqrt{3(3+2)} \\ \mu =\sqrt{15}B:M \\ {\left[Fe{\left(H_{2}O\right)}_6\right]}^{+2}F{e}^{+2} :3d^6 \end{gathered}$$
$H_{2}O:$  Weak field ligand 
No.of unpaired $e^{-}=4$

$$\begin{gathered} \mu =\sqrt{4(4+2)} \\ \mu =\sqrt{24}B.M \end{gathered}$$