Valence Shell Electron Pair Repulsion
Sulfur hexafluoride has 6 regions of electron density around the central sulfur atom (6 bonds, no lone pairs). The resulting shape is an octahedron with 90° F-S-F bond angles.
Related structures H2O | NH3 | CH4 | PF5 |SF4 |ClF3 | SF6 | XeF4