The paper presents a reliability driven decision support approach to study the effects of defect repository patterns on software release decisions as the systems evolve with continuously changing requirements. The proposed approach called 6C evaluates the suitability of existing reliability models in guiding release decisions and provides different solution alternatives with respect to some project specific parameters for making such decisions. The case study conducted with the approach reveals the impact of project and domain specific uncertainty factors such as risk, testing effort and target reliability on time to market decisions for the software release when the underlying assumptions made by existing reliability models are violated.