The paper analyzes routing protocols in mobile ad-hoc networks (MANETs) with a focus on AODV, DSDV, and DSR, proposing an improved version for enhanced cooperative transmission. It introduces the Opportunistic Minimum Cost Cooperative Transmission Shortest Path (OMCTSP) algorithm to optimize energy efficiency and minimizes transmission power, while demonstrating significant performance improvements over existing protocols. By leveraging cooperative communication and local retransmission strategies, the proposed O_CORMAN routing scheme effectively addresses energy consumption challenges in MANETs.