The hybridisation of [Co(NH3)6]^(+2) is dsp². Why is it so please tell me the whole process?

The hybridization of Co^2+ in this coordination compound is not dsp^2 , it is d2sp3.In exited state one of the 3d electrons of Co2+ (3d7) transfers into 5s orbital and the other 6 electrons of 3d orbital pair and remain in 3, 3d orbitals.dx^2-y^2 & dz^2 remain empty.Then 2 inner 3d, one outer 4s & 3 outer 4p hybridize to form 6 equivalent d2sp3 hybrid orbital.Then 6 NH3 gives 6 electron pairs & create 6 coordinate bonds to form octahedral [Co(NH3)6]^2+ ion.It shows paramagnetic property as it has a unpaired electron in 5s orbital.