An ad-hoc network is referred as wireless network in which the nodes in the network are independent of each other and free to move. Since nodes are independent, there is a great extent of loss of packet data while transferring the packet from source to destination. There is a chance of some nodes to be misbehaved. This unsecured ad-hoc network environment is caused due to the dynamic nature of networks and node mobility. Key management is also difficult in ad-hoc network. Several researches have proposed techniques using clusters for an efficient communication from one network to other network. The previous work presented a fully-distributed ID-based Multiple secrets Key Management scheme (IMKM) for a secure communication. Using cryptography and ID based secret key, group key management is done. It provides an authentication about the nodes in the networks efficiently. But the drawback is that it consumes more bandwidth usage for a secure communication and the clustering with IMKM is also unreliable and it takes several rounds to identify the secure channel. In this work, we are going to present a Self Re-Organizing Node Clusters for Secured Ad Hoc Communication. The proposed work present a secured key model for ad hoc network with efficient node clustering based on reputation and ranking model. Misbehavior and selfish nodes in ad-hoc network are detected efficiently with reputation ranking. With the evaluation of normal co-operative nodes, clustering of node is reorganized on its own (self). It does not allow any unauthorized node to involve in the communication between the nodes in ad-hoc network. The Simulation of our work is done for varying topology, node size, attack type and intensity with different pause time settings. The performance metrics used in the evaluation are node reputation count, node density, and attack intensity, response time for malicious node detection, cluster size, and cluster purity index. © 2012 EuroJournals Publishing, Inc.