An alternative refrigerant used for HVAC systems is R32 (difluoromethane). This has a low Global Warming Potential (GWP), but it is flammable (class A2L). The current study uses Fire Dynamics Simulator (FDS), an open-source software, to explore the formation of R32-air mixture in a room/compartment in events of leakages with varying mass flow rates. Firstly, a validation study has been performed using the experimental data from literature for a given scenario of R32 leak. After validation, parametric study has been extended by varying the mass flow rates of the leakage and their resultant effects on mixture formation within the domain over a period of time. The mass flow rate has been varied in the range of 150 g/minute to 350 g/minute. Variation of R32 volume fraction across the room is reported two-time instants. At lower mass flow rates, it is observed that the mixture homogenizes across the domain with no or little flammable patches. However, at higher mass flow rates, flammable patches are observed just below the leakage vent.