Answer : The electronic geometry and the molecular geometry of the molecule will be octahedral.
Explanation :
Formula used :
[tex]\text{Number of electron pair}=\frac{1}{2}[V+N-C+A][/tex]
where,
V = number of valence electrons present in central atom
N = number of monovalent atoms bonded to central atom
C = charge of cation
A = charge of anion
The given molecule is, [tex]PF_6^-[/tex]
[tex]\text{Number of electrons}=\frac{1}{2}\times [5+6+1]=6[/tex]
The number of electron pair are 6 that means the hybridization will be [tex]sp^3d^2[/tex] and the electronic geometry and the molecular geometry of the molecule will be octahedral.