Effectively broadcasting extremity messages in vehicular ad hoc networks is an important issue in VANETs. Real-time good fare message interchange is one of the most crucial subjects in VANET, and well fare message interchange mostly happens between close neighbors. By using this characteristic, we will give power control technologies which depend on connectivity, which diminish the access delay of safety packets. The dominant desire of VANET is to furnish life safety on the road. To obtain this, vehicles make use of two types of safety messages, first one is periodic safety messages in which vehicle speed and location will be given and another one is event-driven messages, which will telecast in case of an emergency environment for example accidents, hard-braking and many more. Our research work will be based upon to control power in control in extremity condition because power is one of the important parameters which we need to utilize efficiently so that optimum result can be achieved. Beside this, we deeply studied diverse routing protocol which will be useful to control power in an emergency situation, attack, and challenges which we have to face in implementing VANET.