The swiftly growing structure of urbanization and smart cities facilitating the transportation era at peak. Thus, the rising pattern of conventional automobiles leading to the high contribution of greenhouse gas (GHG) emission. To mitigate the hazardous profile of GHG emissions, the electric vehicles (xEVs) as the part of smart cities, are gaining immense consideration. However, the unscheduled EVs connectivity with conventional grid system leading unreliable and interrupted power supply, which may lead to the grid failure. In such state of affairs (i.e. GHG emission and rising power demand), the smart microgrids including Renewable Energy Sources (RESs) based charging infrastructure are becoming the most viable paradigm. In this paper, two most emerging technologies belonging to smart cities i.e. xEVs and RESs based smart Microgrid has been covered. The xEVs part of the presented manuscript discusses the detailed study of rising advancement in xEVs charging infrastructure, enhancement in international standards for proper xEVs deployment, and state of art in the xEVs application such as the vehicle to grid (V2G) and vehicle to home (V2H). The second part of the presented work elaborates the state of art in research of smart microgrids energy management system (EMS) including xEVs to enhance the reliability of charging infrastructure.