The spin orbit interactions (SOI) of light mediated by single scattering from plasmon resonant metal nanoparticles (nanorods and nanospheres) are investigated using Jones and Mueller matrix polarimetry formalism. The effect of neighboring resonances in plasmonic nanostructures (e.g., orthogonal electric dipolar modes in rods or electric dipolar and quadrupolar modes in spheres) on the individual SOI effects are analyzed and interpreted via the Mueller matrix-derived polarimetry characteristics, namely, diattenuation d and retardance δ. The results clearly reveal that each of these can be controllably tuned and enhanced by exploiting the interference of neighboring modes.