We have theoretically and experimentally investigated the dielectric behavior of NixCo1-xFe2O4 nanoparticles (NPs) (where x=0.0, 0.6, and 1.0), which have been synthesized by microwave induced combustion synthesis using urea as fuel. A variation of complex dielectric permittivity at room temperature with frequency in the range 1 MHz-3 GHz has been studied. The permittivity displays atomic polarization and electronic polarization. Particles showed phase purity and crystallinity in powder x-ray diffraction (XRD) analysis. At the same time, NixCo1-xFe2O4 NPs demonstrated a spinel cubic structure from XRD results.