A vehicular ad-hoc network (VANET) is a type of ad-hoc network that has gained high attention over the past few years and is extensively used in safety critical applications in case of emergency like road accidents. The proper working of VANET in these safety critical applications requires the need of VANET supporting timely and reliable delivery of the data to the receiver vehicles. However, supporting both timely and reliable delivery of the data messages to the receiver has become highly challenging in VANET because vehicle mobility, dynamic mobility pattern of the vehicles, dynamic network topology, and error-prone wireless communication channel. In this paper, this challenge is addressed by proposing Relia-MAC framework that adds timing properties to the novel Adaptive Byte-Hybrid Automatic Repeat request (AB-HARQ) method. The uniqueness of this paper lies in developing a single framework which when implemented in a vehicular ad-hoc network can assure both timely and reliable delivery of the data packets. Both analytic model and simulation studies are used in this paper to evaluate the effectiveness of proposed framework. The simulation studies have identified the effectiveness of Relia-MAC framework in recording higher ring throughput value and packet delivery ratio.