A method and system for assigning priority to a talk group of a plurality of talk groups in a communication network (100) is provided. The method includes detecting (304) activity on a first talk group (108) via a Vehicular Repeater (VR) (106). The first talk group is associated with a lower priority than that of a second talk group (110). The method also comprises assigning (306) a higher priority to the first talk group and the lower priority to the second talk group, based on the step of detecting. Further, the method comprises dynamically re-assigning (308) the higher priority and the lower priority amongst the plurality of talk groups, based on detecting activity.