Nowadays MANETs have obtained a sensible interest due to the growing number of wireless device users. Hence, Mobile Ad-Hoc Networks are used in real time applications, and these real time programs need QoS assurance in terms of throughput and delay. Hence, it assets the QoS in MANETs. The main problem is the communication which is more a shared standard in a particular channel. In this work, the authors suggest an Achievable Throughput based Admission Control Protocol (ATACP) for controlling a channel from becoming overloaded, thereby making sure an assured throughput for real time traffic. Achievable Throughput based Admission Control Protocol works on a cross layer structural design that encompass the network and the MAC Layer and the admission control is carried in each node during the path discovery. The node broadcasts the route request to its neighbors providing its achievable throughput that satisfies the desired throughput considering the contention count. The performance of the ACP maintains the ineffective overhead throughput and End-to-End Delay MANETs. This work proposes the improving routing mechanism in MANETs using discovery routing protocols to achieve the effectiveness of throughput and less end-to-end delay over Mobile Ad-hoc Network.