Increasing the fuel demand brings us to find out the various alternative solutions. Out of the various research activities, bio-diesel from various oil seeds is the major activity, which decides the future energy sources. Our previous researchers concluded that Jatropha oil is to be an alternate fuel for Compression ignition (C.I) engines and it has closer characteristics of diesel fuel. Still this oil cannot be utilized directly because of its physical and chemical characteristics. This article relating the Jatropha oil's physical and chemical characteristics, production techniques, how it is treated as an alternate for diesel fuel, comparison characteristics of Jatropha oil with conventional diesel fuel, finally the suitability parameters for diesel engine. The required fuel properties of biodiesel such as density, kinematic viscosity, calorific value, flash point, pour point, Cetane number, carbon residue and specific gravity were theoretically found. The various results with different blends of diesel and Jatropha oil (considering 0%, 10%, and 20%) on single cylinder direct injection engine were experimentally found. Based on this, the engine characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust temperature are calculated manually. And also the emission characteristics are plotted with various aspects. These results indicating the optimum blend, which can be suitable for using as alternate fuel in diesel engine.