According to VBT, the shape of [CoF6]-3 is octahedral.
The element Cobalt belongs to group VIII of the periodic table. It is similar to iron and nickel in its physical properties. The electronic configuration of cobalt is [Ar] 3d74s2.
Co is in +3 oxidation state in the complex [CoF6]-3. Hence [CoF6]-3 is sp3d2 hybridized and the shape is octahedral.