Potential role of nanofiller in deciding their localization in polypropylene (PP)-natural rubber (NR) blend system is evaluated using experimental techniques followed by authentication using various theoretical approaches. Thermoplastic elastomers (TPEs) of PP-NR blend-based nanocomposites with Cloisite 15A and titanium dioxide (TiO 2) were prepared by melt mixing method, using Haake rheocord-90. In prefixed blend composition of 70-30 (PP-NR), selective localization of nanofiller was determined by transmission electron microscopy (TEM), and quantified by Harmonic mean theoretical studies. Correlation length (ξ clay) and average length of the clay layers (L clay) measured for the dispersion of nanoclay. The dispersion efficiency of Cloisite 15A and TiO 2 in blend matrix were determined by X-ray diffraction (XRD) studies. Mechanical properties of blend nanocomposites were examined by varying the nanofiller loading and compared with theoretical approaches such as Kerner, Guth, Halpin-Tsai, Einstein and Quemeda models. It was found that irrespective of the geometry, the fillers migrated to the