This research examines the effectiveness of indirect monetary policy tools, specifically open market operations (OMO), on Iran's financial and economic stability. To this end, a real-time dynamic stochastic general equilibrium (DSGE) model is developed for the Iranian economy. Utilizing Bayesian estimation techniques on seasonally adjusted time series data spanning 1991-2022, the model parameters are estimated, and its input values are determined. Simulation results demonstrate the model's ability to accurately capture the fluctuations of the Iranian economy. Dynamic analysis reveals that expansionary monetary policy implemented through OMO exerts a positive influence on real and financial sector variables, including investment, output, and employment. However, it also leads to an increase in inflation. Furthermore, this monetary policy instrument can be effectively employed to mitigate excessive volatility in the policy rate, which can negatively impact private sector expectations.