The number of species from the following that are involved in \( sp^3d^2 \) hybridization is: \( \mathrm{[Co(NH_3)_6]^{3+}} \), \( \mathrm{SF_6} \), \( \mathrm{[CrF_6]^{3-}} \), \( \mathrm{[CoF_6]^{3-}} \), \( \mathrm{[Mn(CN)_6]^{3-}} \) and \( \mathrm{[MnCl_6]^{3-}} \)