In multi-hop wireless mobile ad hoc network each node is capable of sending, receiving and forwarding data packets. Since it is an infrastructure-less networks, it makes it feasible to set up at anyplace and at any time. Supporting Quality of Service (QoS) in such network is a challenge due to limited available resources like bandwidth etc. This paper describes a new approach of Medium Access Control (MAC) which supports QoS for real time applications. Each node is assigned priorities dynamically based on their roles (as sender, receiver or forwarding node) and type of traffics (Real Time Packet - RTP or Non Real Time Packet - NRTP) in the networks. This approach enhances QoS for Real Time data in terms of bandwidth utilization and delay. This ensures higher network throughput with lower delay for packet delivery. New queue has been designed to fit in to the proposed MAC protocol. Simulation shows that our proposed MAC performs much better than the standard IEEE 802.11 DCF in terms of average throughput, delay, MAC overheads in support of RTP and fairness within a class of traffic also increases.