The total number of unpaired electrons present in the d^3, d^4 (low spin) d^5 (high spin), d^6 (high spin) and d^7 (low spin) octahedral complex…

The total number of unpaired electrons present in the $\displaystyle \mathrm{d}^3, \mathrm{~d}^4$ (low spin) $\displaystyle \mathrm{d}^5$ (high spin), $\displaystyle \mathrm{d}^6$ (high spin) and $\displaystyle \mathrm{d}^7$ (low spin) octahedral complex systems is $\displaystyle \_\_\_\_$.