Protocols are required to optimize network performance based on energy resource due to limited battery power in Mobile Ad hoc NETwork (MANET) nodes. This paper proposes a modified Protocol for MANET to achieve energy efficiency and reliability. The probability for a sleep node is determined by the parameter metric of Packet Delivery Ratio at the destination node. The probability value can be adaptively adjusted by Radio Activated Switch (RAS) which is embedded in each node. This results in less amount of energy consumption and more reliability in mobile ad hoc network. User datagram protocol and transport control protocol based traffic models are used to analyze the performance of this protocol and NS-2 simulator is used.