As per the previous literature, there is wide usage of diesel (or) fossil fuels worldwide. In India, due to the vast and growing population dependence on oils (or) fossil fuels, the usage of fossil fuels is increasing, resulting in the consequent impact of global warming issues and pollutants being released into the environment. So there is a need for an alternative solution (or substitute), and with the use of bio-diesel, the pollutants will be reduced in the environment. Bio-diesel is extracted from edible and non-edible blends. Further, extracted oil is processed through transesterification. The main parameters on which the transesterification process depends on the selection of catalyst type, molar ratio (alcohol: oil), type of alcohol used, reaction temperature, time, etc. The main theme of this paper is to review the studies carried out by the research in the last few years.