Spin only magnetic moment of MnBr 6 4 - is _____ B.M. (round off to the closest integer)

${\left[{\mathrm{MnBr}}_6\right]}^{4-}$

${\mathrm{Mn}}^{2+}: \left[\mathrm{Ar}\right]3{\mathrm{d}}^5$

Number of unpaired electrons $=5$

Magnetic moment of the complex,

$\mathrm{\mu }=\sqrt{\mathrm{n}(\mathrm{n}+2)} \mathrm{B}.\mathrm{M}=\sqrt{35}=5.91 \mathrm{B}.\mathrm{M}$.

5.91 is rounded off to the nearest integer 6.