The traditional electricity grids are increasingly the information is connected with cyber-infrastructures and communication technology (ICT) sector’s rapid advancements, where cyber attacks risks are also increases. Cyber-attacks are thought to represent a certain type of high-impact/ low likelihood contingency that might have disastrous repercussions on power systems, including shedding of load, uneconomical, operating of units under overload, or, worst of all, failure of load and shut down of load. The goal of this project is to solve To find the ideal plan of production units, including their turning on/off condition and ideal dispatching in the circuit and connection, one must solve Network-Constrained UC (NCUC) problem for a typical case that has a day-ahead horizon. This project attempts to solve cyber security Unit Commitment problem for determining the optimal generation timing for a daily bases, weekwise or monthly bases when there was Load Redistribution (LR) cyber attacks. This work gives alarm indication to the personnel about the severity of the attack. Permissible overloading limitation for the system network is the outcome of the project.