Plasmonic quasicrystals stand out as the center of cynosure behind the many potential applications which emerges due to the quasi-periodic structure and metal dielectric patterns. The rotational symmetry elicits the optical properties resembling like crystals and and the metal dielectric nanostructure are being probed and explored in various disciplines of science and even in engineering also. Plasmonic quasicrystals composed of quasi- periodic and metal-dielectric patterns furnish efficacious benefits in improving the efficiency of solar cells, broadband transmission enhancement, and bio-sensing applications etc. Due to the intriguing properties of plasmonic crystals such as periodicity and short range ordering, the excitation of the surface Plasmon polaritons is restricted by a few fewer techniques such as polarization, launch angle dependence. Polarization contains wealth of information and holds the potential to control the interaction of light with metal Nano particles. Therefore, an exhaustive and thorough information regarding incident and scattered light is necessary for the examining the spectral response of the quasi crystal. Here, we report to the best of our knowledge the first ever quantitative polarimetric studies on the extremely complex plasmonic quasicrystal by recording a full 4x4 spectral Mueller matrix from the same and tried to explore the fascinating and interesting properties of quasi crystals. A homebuilt comprehensive Mueller Matrix platform (integrated with dark field microscope) is utilized to record the conventionally weak, intermixed polarization signal from plasmonic quasicrystals. These studies probed the enthralling phenomena of Fano resonance, explored and probed the presence of phase anisotropy in the plasmonic quasicrystals using the Mueller matrix derived retardance (δ) parameter. Additionally polarization mediated tuning of Fano Resonance is achieved too. Moreover it is demonstrated that the Mueller matrix derived diattenuation, retardance parameters probes the Fano resonance, phase and amplitude anisotropy from such complex plasmonic nanostructure and proved instrumental in polarization controlled tuning of Fano resonance.