The Internet of Things (IoT) paradigm is a predominant research domain for smart cities, smart villages, society, and industry 4.0. The introduction of Unmanned Aircraft Systems (UAS) in an ultra-low latency network with fog, dews, and edge computing gives the researcher ample scope to establish a decentralized architecture for ultra-high-speed message exchange between IoT devices. This work mainly focused on Social Internet of Things ecosystem and its design to efficiently handle large group social gatherings, events, and emergency service management. We propose a layered message transfer framework for the social IoT scenario. We also establish network connection through flying ad hoc network architecture. The standard IoT message transfer protocol is redesigned by amalgamating with an opportunistic routing mechanism and deployed within 6G software-defined network (SDN) slice. We use seven distinguished network slices for different services and corresponding access. The study reveals nearly 99% of message delivery rate with a latency upper bound of 2300 ms by opportunistic message transfer scheme in a dense network scenario for QoS 2. It also shows 95% of the bandwidth utilization per slice and 97% of network coverage under SDN in quality of service level 2. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.