Abstract 1: The discovery of quasars at redshift z>6 has presented a significant challenge in understanding the origin and evolution of these early quasars. Addressing these questions within the context of galaxy evolution is a fundamental objective of N-body hydrodynamical simulations. In this study, we utilize the IllustrisTNG simulation to investigate how parameter choices, including seed mass and seed redshift, impact the population of supermassive black holes (SMBHs) in simulations. Our analysis reveals a correlation between the seed redshift of SMBHs and their mass at redshift z = 0. Furthermore, we assess the prevalence of Milky Way analogs within the simulated galaxy population and identify a limited number of three true Milky Way analogs. Lastly, we explore the accretion history of SMBHs in the simulation, shedding light on their growth over cosmic time.