  Heavy quarks are excellent probes to understand the hot and dense medium
formed in ultra-relativistic collisions. In a hadronic medium, studying the
transport properties, e.g. the drag ($\gamma$), momentum diffusion ($B_{0}$),
and spatial diffusion ($D_{s}$) coefficients of open charmed hadrons can
provide useful information about the medium. Moreover, the fluctuations of
charmed hadrons can help us to locate the onset of their deconfinement. In this
work, we incorporate attractive and repulsive interactions in the
well-established van der Waals hadron resonance gas model (VDWHRG) and study
the diffusion and fluctuations of charmed hadrons. This study helps us
understand the importance of interactions in the system, which affect both the
diffusion and fluctuations of charmed hadrons.
