Number of ambidentate ligands in a representative metal complex M ( en ) ( SCN ) 4 is _ _ _ _ _ _ _ _ _ . […

Ambidentate ligand has two or more donor atoms, but during complex formation, only one donor atom is attached to central metal. ${\mathrm{SCN}}^{-}$ ion has donor atoms $\mathrm{N}$ and $\mathrm{S}$. 

Examples of ambidentate ligands include ${\mathrm{NO}}_2^{-} \mathrm{and} {\mathrm{SO}}_3^{2-}$. So,$4 {\mathrm{SCN}}^{-}$ ligands are ambidentate.