In Mobile Ad-hoc Network (MANET), portable devices like smartphones, or laptop PC can join together to make provisional networks without any infrastructure The objective of multicast or unicast protocols is to ensure an efficient route formation and flow control mechanism which is a very challenging issue for many group computing services in MANETs. MANETs can support several real-time applications like emergency rescue, and disaster relief operations which require minimum Quality of Service (QoS) to handle high traffic. Providing QoS for multimedia and group-oriented computing in MANETs becomes a real challenge due to the wireless medium and the mobility of operating nodes. Therefore, an investigation of routing protocols for one-to-many or many-to-many computing is important that supports acceptable QoS in MANETs. Numerous QoS metrics have been considered for the assessment like packet delivery ratio, latency, packet loss rate, control overhead, and throughput. By considering different network topologies and scenarios with different performance parameters, the primary goal of this study is to explore the challenges and factors for QoS services in MANET’s multicast communication. The outcomes of investigation can be used to design the future MANET protocol for multimedia applications. The performance results indicate that the increasing number of sending/receiving nodes may increase the overhead or latency of the network but capable of providing higher network throughput, carried out in NS-2. The results also indicate although MANETs can induce errors and packets are lost as part of the normal operating context, multicast AODV practice superior to the unicast protocol to various QoS in a wide range of scenarios with less overhead.