The electronic structure of PuB6, an actinide analog of SmB6, was investigated making use of a combination of the density functional theory (DFT), and the exact diagonalization (ED) of an effective discrete Anderson impurity model. Intermediate valence ground state with the f-shell occupation n(4f) = 5.5 for the Pu atom in PuB6 is calculated. The 5f-shell magnetic moment is completely compensated by the moment carried by the electrons in the conduction band. Already in DFT, PuB6 is an insulator with a small amount of holes near the X-point, and the indirect band gap of approximate to 60 meV. This band gap becomes direct in DFT+ ED calculations supporting the idea of ``topological Kondo insulator{''} in PuB6. Connection between the electronic structure of PuB6 and-Pu is established. We propose that these materials belong to a new class of intermediate valence ``Racah{''} materials with the multi-orbital ``Kondo-like{''} singlet ground-state.