MANET is the collection of various wireless mobile nodes. Security is of high concern in mobile ad hoc network as it has no centralized authority which can oversee the particular node working in the network. The attacks can be preformed from both inside and outside the network. Nodes within surrounding to gain common radio link can be often used to set up ad hoc infrastructure. But the safe communication between mobile nodes needs the secure communication link to interact in network. This paper focus the security and reliability of mobile ad hoc network from Banzantine attack with the help of mean-field game theory.