Due to the rapid development in Wireless Ad-hoc Networks, spatial reuse plays a significant role in refining network capacity. Cooperative communication is a scheme that enables proficient utilization of communication resources and entailed Quality of service (QoS) by exploiting transmit diversity property of MIMO technique. Two leading technologies that can influence the future of wireless networks are Co-operative communication and Directional antenna systems. Directional antenna leads to substantial increase in coverage range, spatial reuse, and overall network capacity. However, combining cooperative communication and directional antenna is a challenging process which involves issues in proper relay selection [2]. We propose a decentralized cross layer protocol, namely, Cooperative Omni-steerable Routing Protocol (COSRP) for wireless Adhoc network. In COSRP the relay selection is based on highest residual battery of a node. Further each node intelligently switches from omnidirectional beam to omni-steerable directional [OSD] beam in cooperative mode. In this paper we enhance the CORB protocol by leveraging physical and network layer co-ordination that was not accomplished in the CORB protocol [13]. During Direct transmission of data, every node uses omnidirectional beam, When the Packet Reception Ratio [PRR] reaches below threshold, cooperative communication is enabled which in turn activates OSD beam in Source, Relay and Destination. The proposed protocol brings coordination between Network layer and Physical layer to effectively utilize the benefits of Cooperative communication and Directional antenna. By analyzing various simulation studies, the results prove that proposed COSR protocol boost the throughput and packet reception. Since, relay selection and monitoring of antennas is done in Network layer overall network performance improved.