Atmospheric radical chemistry determines the atmospheric composition, fate of trace species, secondary production including formation of organic aerosols and harmful tropospheric ozone (O3). Chlorine radicals (Cl•) have a pivotal role in air quality under contrasting urban atmospheric chemistry. Even in trace concentration Cl• is a critical oxidant in urban atmosphere.  Cl• has analogous reaction mechanism to OH• and having noted that Cl• have much faster reaction rates than initiated by OH•. The nocturnal reactions of N2O5 on Cl-rich aerosols affect NOx recycling, oxidation of VOCs and increases levels in particulate matter in winter mornings, thus posing serious threat to human population and reduces visibility. Abundance of Cl• highly depends on regional emissions and Indian region is prone to high chlorine rich PM and notably, northern India falls under most polluted regions globally.  Despite its importance, chlorine chemistry is often overlooked in atmospheric models, underestimating pollution levels.The work utilizes 3D GEOS-Chem model, integrated with anthropogenic HCl emissions coupled with heterogeneous N2O5 + Cl chemistry to evaluate the impact of chlorine chemistry on air quality over Indian region. It includes model's capability in reproducing observations and their distributions, quantifying the changes in total PM2.5 and surface O3. The model successfully reproduces observations, quantifying the effects of chlorine emissions on regional air chemistry. This study provides insights into the distribution of reactive chlorine species, limiting processes, impact on atmospheric oxidative capacity, chlorine-initiated oxidation of VOCs and changes in the levels of atmospheric pollutants. It underscores the necessity of incorporating chlorine emissions and mechanisms into models to accurately predict and understand air quality in India. Further results will be shared at the later stage providing a detailed and its potential effects regional air quality.