  An experimental setup consisting of 12 layers of glass Resistive Plate
Chambers (RPCs) of size 2\,m\,$\times$\,2\,m has been built at IICHEP-Madurai
(\ang{9;56;14.5}\,N \ang{78;00;47.9}\,E, on the surface) to study the long term
performance and stability of RPCs produced on large scale in Indian industry.
This setup has been collecting data triggered by the passage of charged
particles. The measurement of the multiplicity of charged particles due to
cosmic ray interactions are presented here. Finally, the results are compared
with different hadronic models of the CORSIKA simulation.
