This comprehensive research study examines the cybersecurity aspects of integrating Wi-Fi 6, ZigBee, and Li-Fi technologies within smart city ecosystems. The paper analyzes the security risks, threats, and necessary mitigation measures to ensure the confidentiality, integrity, and availability of transmitted data. It explores data protection methods in Wi-Fi 6 networks, security of ZigBee automation systems, and the unique security advantages of Li-Fi technology. The study also proposes the integration of security systems into a unified smart city management platform leveraging blockchain and AI, enhancing overall resilience. The findings provide practical implications for smart city stakeholders and contribute to the advancement of secure and resilient urban infrastructure.