The Volume of Fluid (VOF)-Lagrangian Particle Tracking (LPT) coupled algorithm is used in this work to numerically model the breakup of a liquid jet in coaxial flow. Ligament formation arises within the liquid jet's core due to its interaction with the co-flowing air. These ligaments subsequently undergo fragmentation, yielding a spectrum of droplet sizes. This intricate process is further modeled using a Lagrangian stochastic spray model, providing insight into the secondary breakup dynamics. Moreover, our study delves into analyzing the instability within the liquid jet. This examination contributes to a comprehensive understanding of the multifaceted behavior exhibited by the liquid spray and its eventual transformation into an array of droplets of varying sizes.