All inner orbital complexes are low spin complexes.
Hybridisation involves the pairing of electrons in the inner d orbitals. The higher-energy orbitals are also unoccupied. As a result, there are lesser or no unpaired electrons present. Therefore, the inner orbital complexes have low spin.
High Spin and Low Spin
The complexion with the greater number of unpaired electrons is known as the high spin complex, the low spin complex contains the lesser number of unpaired electrons. High spin complexes are expected with weak field ligands whereas the crystal field splitting energy is small Δ. The opposite applies to the low spin complexes in which strong field ligands cause maximum pairing of electrons in the set of three t2 atomic orbitals due to large Δo.