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We present our results on the shear viscosity to entropy ratio ( η/ s) in the framework of the clustering of the color sources of the matter produced at RHIC and LHC energies. The onset of de-confinement transition is identified by the spanning percolating cluster in 2D percolation. The relativistic kinetic theory relation for η/ s is evaluated using the initial temperature ( T) and the mean free path ( λ). The analytic expression for η/ s covers a wide temperature range. At T∼150 MeV below the hadron to QGP transition temperature of ∼168 MeV, with increasing temperatures the η/ s value drop sharply and reaches a broad minimum η/ s∼0.20 at T∼175-185 MeV. Above this temperature η/ s grows slowly. The measured values of η/ s are 0.204±0.020 and 0.262±0.026 at the initial temperature of 193.6±3 MeV from central Au+Au collisions at $\sqrt{s_{NN}}=200~\mathrm{GeV}$ (RHIC) and 262.2±13 MeV in central Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76~\mathrm{TeV}$ (LHC). These η/ s values are 2.5 and 3.3 times the AdS/CFT conjectured lower bound 1/4 π but are consistent with theoretical η/ s estimates for a strongly coupled QGP. [ABSTRACT FROM AUTHOR]