In the present research, we have studied the manganites for their promising applications in magnetoresistive, bolometric (infrared detectors) and magnetic refrigeration based devices. In order to explore the manganite for different applications near the room temperature, we have investigated Nd0.5La0.2Sr0.3MnO3: xAg2O (x = 0-30 wt%) polycrystalline composites synthesized by solid state reaction route. These composites have been found to be crystallized in orthorhombic structure with Pnma space group. The lattice constants and volume of the unit cells have not been substantially changed, but the transport properties have been greatly influenced with addition of silver oxide. A significant improvement in magnetoresistance (MR%) has been observed from 22% (for x = 0.0) to 47% (for x = 0.3) in an applied magnetic field of 1 T. The temperature coefficient of resistance (TCR %) has been found to be increased from 2.9% (for x = 0.0) to 7.4% (for x = 0.3) with addition of silver oxide. Moreover, the change in magnetic entropy(-ΔSM) near the room temperature is slightly varying from 3.94 J/ kg K-1(for x = 0.0) to 3.59 J/kg K-1(for x = 0.3) within the field of 6 T. A significant improvement of MR in presence of low magnetic field and enhancement in the TCR % have been observed, but the change in magnetic entropy varied slightly with addition of silver oxide to the pristine compound. © Springer Science+Business Media New York 2016.