Ever necessity of tremendous data traffic and mas-sive deployment of industrial Internet-of-Things (IIoT) devices operating in higher bands, i.e., millimeter-wave (mmWave) and terahertz (THz), have encouraged academia and industry to transition towards the future sixth-generation (6G) wireless communication networks. Nevertheless, the recent emergence of 6G enablers, i.e., reflecting intelligent surface (RIS) and massive multiple-input multiple output (mMIMO), has the ability to po-tentially change the previous paradigm of indoor mm Wave wire-less communication by modifying the propagation environment. It can control and establish the favorable and tunable wireless channel responses by exploiting the multipath and diversity of the propagation environment. Therefore, this next cutting-edge technology is capable of massively improving the performance of mmWave-mMIMO-enabled IIoT data transmissions, making it a feasible solution for 6G networks. In this paper, we propose a RIS-assisted mmWave-mMIMO for a multi-cells indoor factory propagation environment, which provides, 1) aid in mitigating the impact of radio frequency (RF) interference from interferes in closed vicinity (i.e., neighbor cells) by employing metasurface laminated walls, and 2) increased the mmWave-mMIMO sys-tem performance by controlling and tuning the indoor factory channel conditions. Our results indicate that the proposed RIS-assisted mmWave-mMIMO system outperforms the benchmark link capacity performance in the presence of interference.