Low cost, earth abundant, rare earth free magnetocaloric nanoparticles have attracted an enormous amount of attention for green, energy efficient, active near room temperature thermal management. Hence, we investigated the magnetocaloric properties of transition metal based (Fe₇₀Ni₃₀)_100−xCr_x (x = 1, 3, 5, 6 and 7) nanoparticles. The influence of Cr additions on the Curie temperature (T_C) was studied. Only 5% of Cr can reduce the T_C from ~438 K to 258 K. These alloys exhibit broad entropy v/s temperature curves, which is useful to enhance relative cooling power (RCP). For a field change of 5 T, the RCP for (Fe₇₀Ni₃₀)₉₉Cr₁ nanoparticles was found to be 548 J-kg⁻¹. Tunable T_Cin broad range, good RCP, low cost, high corrosion resistance and earth abundance make these nanoparticles suitable for low-grade waste heat recovery as well as near room temperature active cooling applications.