As we already know, we will not apply VSEPR theory here, because according to VSEPR Theory,
ep = (6+5)2 = 112
Now, we will apply AVSEPR Theory.
Central atom will be S [Because of the presence of d-orbitals] and In VSEPR Theory, we ignore oxygen.
Therefore, number of Ligands = 4 [only Fluorine's ignoring oxygen]
Valence electrons in S = 6
Therefore, number of electron pairs = (6+4+0−0)2 = 5