The increasing inexpensive Wireless Networking hardware has incorporated the mobility support into the existing Wired Networks that must support the data and real time application such as rescue operations, military, hospitals etc. Mobile Ad hoc networks (MANETs) play an important role in the deployment of future Wireless Communication Systems. These networks are required to provide efficient quality of service (QoS). To facilitate communication within the network, efficient routing algorithms are required to create, maintain and repair paths with a minimum overhead. Here we have discussed many protocols that support QoS in different ways using various Network and Communication models. We have focused on providing QoS in different routing techniques using various QoS parameters such as, Network Lifetime, Routing Overhead, Packet Loss, end-to-end Delay, Energy Consumption, Packet Delivery Ratio. Various algorithms have been proposed and their performance is analyzed and compared with existing techniques. The results and the Literature Survey are useful for students and research community, who are working on Ad hoc Networks, Sensor Networks, Mesh Networks, etc.