The document discusses the development of a Priority Based Flow Control Protocol (PFCP) designed for IoT applications utilizing Light Fidelity (LiFi) networks, addressing the need for efficient data transmission of critical information. The PFCP modifies existing Transmission Control Protocol (TCP) variants to prioritize critical data flows during congestion, thereby enhancing the goodput and packet delivery ratio in IoT environments. Through simulations, it demonstrates improved performance for prioritized flows compared to non-prioritized ones in both error-free and error-prone conditions.