This paper deals with the finite capacity unreliable single server queueing model under admission control F-policy with balking and feedback. F-policy deals with controlling the arriving customers in the system. In F-policy, if the system capacity is full (say K) then further customer is prohibited from admission to the system. The new admission of the customer is allowed into the system when system capacity decreases to a threshold value F (0 ≤ F ≤ K − 1). The concept of balking is incorporated to reduce the waiting line of the customer. The idea of server breakdown and repair is also added. The steady-state system probabilities and several performance indices are derived by using the Gauss-Seidel method. We construct the cost function and minimize it by using the direct search method. The cost minimization corresponding to the optimal service rate is also presented. We also present the numerical result under the optimal operating condition.