When 1-s 3-p and 2-d orbitals combine to form a hybrid orbital, it leads to formation of 6(s+p+p+p+d+d) hybridized sp³d² orbitals. which adopt octahedral arrangement.

eg. SF₆

 

 

In SF₆, the central atom S has config: 3s² 3p⁴

 

 

 

the paired electron from s and p orbital get promoted to 3d orbital and then hybridize to form sp³d² hybrid orbitals.

Each of the 6 hybrid orbitals overlaps with the 3p orbitals of F to form 6 S-F bonds.