Many researches had tried on Jatropha as a replacement for diesel and confirmed that with minor changes in engine, the efficiency of diesel engine can be improved marginally. But due to the higher viscosity of Jatropha, the flow capacity of Jatropha is less which is the major drawback for increasing the efficiency of engine. To overcome this flow problem, in the present work it is planned to work with nano fluids. Further the work is planned with B20 for varying the proportion of Al2O3 nano fluids (50,100 and 150ppm) with blending of Jatropha biodiesel. The performance of the engine majorly depends on the combustion and the heat available in the chamber. Further it is confirmed that the performance of the engine can be improved with Grooved piston insert in the combustion chamber with various proportions of nano fluids. In this experimental works has been done for calculating the performance and emissions of single cylinder DI diesel engine with Jatropha biodiesel as a fuel by varying the proportion of nano fluid, and also the comparison of the performance and emissions of engine with normal piston(aluminum piston) to the replaced piston(RGP6 piston) has done.