A significant part of an IoT-based smart-system is comprised of a large number of low-cost devices that interact with one another based on low-power wireless communication. Energy-efficient and fast sharing of data plays a crucial role in such massive distributed systems. The topology of the underlying network highly influences the efficiency of a data-sharing process. However, since topological information becomes available only after the deployment of a system, it is hard to design a strategy paying proper attention to this important issue. In this work, we explore how many-to-many data-sharing, which is the most complex and highly important pattern of sharing data, can benefit from the availability of network topology information. We also deal with how the necessary topology information can be obtained in run-time. In particular, we design a Synchronous-Transmission (ST)-based many-to-many data-sharing strategy that can dynamically modulate itself in real-time as per the topology of the underlying network. Through extensive simulation as well as experiments over publicly available IoT-testbeds we demonstrate that the proposed strategy can accomplish all-to-all data-sharing in IoT up to 42.5% faster and consume 43.3% less radio-on time compared to the existing state-of-the-art strategies.