Industrial Internet-of-things (IIoT) networks have recently gained enormous attention because of the huge advantages they offer. A typical IIoT network consists of a large number of sensor and actuator devices distributed randomly in an industrial area to automate various processes, where a major goal is to collect data from all these devices and to process it centrally at an aggregator. However, for an efficient system operation, a proficient scheduling mechanism is required due to its direct association with performance parameters. Many existing techniques such as time division multiple access (TDMA), do not perform well in industrial environments due to their stringent timeliness requirements. In this paper, we propose a medium access control (MAC) layer protocol for node scheduling in a scenario where some devices may not be in one-hop range of the aggregator and thus renders a multi-hop mechanism inevitable. A discrete time Markov chain (DTMC) model is proposed to characterize the transmission of multi-tier nodes and the analytical expressions of throughput and latency are derived. It has been oberved that the delay scales linearly with the number of nodes which are away not in one-hop distance of the aggregator. Numerical simulations have been performed to validate the theoretical results.