Mobile ad-hoc Networks (MANET) with mobile sinks are measured as a practical substitute to the complex deployment of conventional wireless sensing environments. This research concentrates on the high-throughput opportunistic routing with lower delay during the transmission service by the mobile nodes with an arbitrary number of mobile sinks and common network topology. Here a novel opportunistic routing (OR) model known as Delay-Aware Estimated Transmission Rate (DA-ETR) is proposed to evaluate the delay caused due to the intermittent mobile nodes and packet re-transmission process. With the execution of DA-ETR, the work demonstrates the functionality of DA-ETR seamlessly over the ETR. It specifies that the available ETR-based routing protocols for dynamic MANET are extended easily to MANET with minimum modification using the anticipated DA-ETR model. Also, the anticipated DA-ETR model with efficiency measure provides superior throughput and enhances the routing stability of OR. The novelty of the work relies on enhancing the routing performance. Thus, the proposed DA-ETR model seems lightweight and achieves easier deployment with no constant mobility prediction. The DA-ETR model for OR outperforms various existing approaches and shows better performance by achieving scalability, reliability, reduced routing and communication overhead and transmission delay. The proposed model shows a queue length of 6.5 packets, 6.3 packets/node/sec in transmission and reception rate, the delay is 50 ms, storage overhead is 80 packets, communication overhead is 20 packets and 2.5 ms packet loss. The simulation is done in the MATLAB 2020a environment.