Mobile Ad-hoc network is a collection of mobile nodes that form a temporary network without use of any existing infrastructure. Group communication is challenging task in MANET .In recent years many protocols have been developed to achieve group communication in MANET. Since VANET is the subset of MANET the same group communication would be achieved to improve the scalability, reliability and optimality of routing protocols. Using group communication, distributed traffic information system has evolved for detecting traffic problems on road. The traffic information will be communicated to vehicles in the form of V2V or V2I interaction medium. In the existing system, the traffic information with the vehicle id, position, location along with the ad dissemination, driver behavior information will be transmitted to other vehicle which leads to unnecessary tracking of vehicles on the road side. This in case leads to major threats such as attacks, hacking vehicles, etc...Therefore in proposed system the security in VANET is obtained by restricting the unnecessary flow of information like vehicle id or position to other ongoing vehicles on the roadside with the help of trust based reputation system in VANET. The ad dissemination along with traffic information and driver behavior information will be transmitted to other vehicles in the existing system with the help of trust based reputation system in VANET. But since it contains some disadvantages, the fuzzy logic reputation system will be implemented as our future work where the architecture is decentralized.