Identify from the following species in which d ^ 2 sp ^ 3...

${\left[Co{\left({NH}_{3}\right)}_{6}\right]}^{+ 3} - {d}^{2}{sp}^{3}$ hybridization

In ${\left[Co{\left({NH}_{3}\right)}_{6}\right]}^{3 +}$, $Co$ is in $+ 3$ oxidation state with the configuration $3{d}^{6}$. In the presence of ${NH}_{3}$ a strong ligand, the $3d$ electrons pair up leaving two d-orbitals empty. Hence, the hybridization is ${d}^{2}{sp}^{3}$forming an inner orbital octahedral complex. 

${BrF}_{5} - {sp}^{3}{d}^{2}$ hybridization

${\left[{PtCl}_{4}\right]}^{- 2} - {dsp}^{2}$ hybridization

${SF}_{6} - {sp}^{3}{d}^{2}$ hybridization