In this paper, an improved NewReno (iNewReno) TCP protocol has been proposed for futuristic MANETs applications. The iNewReno is a modification to TCP's Congestion avoidance phase;fast retransmission phase and fast recovery phase. In the proposed iNewReno,dynamic congestion window is adopted. A comprehensive experimental study to analyze the performance of iNewReno in various network environments is also presented in this paper. The proposed iNewReno algorithm has considered Round Trip Time (RTT), an average of RTT, and time taken by three duplicate ACK in the congestion avoidance phase. The proposed protocol decreases the delay in the network upto 70–90%, which minimizes the RTT leading to faster retransmission of packets and reduced congestion. Also, in iNewReno, Retransmission Time Out (RTO) is not considered in fast retransmission phase and fast recovery phase. Quantitative and realistic results for both NewReno and iNewReno are evaluated and compared through exhaustive experiments and simulations. It has been evident that different TCP variants have different robustness against mobility, and with a suitable choice of the robust TCP protocol, the network performance improves. The obtained results and analysis are significant and indicate that the proposed algorithm provides an improved performance for a TCP protocol in a given real-time network application.