Solidification and organization of silver nano-particle in a confined region between graphene sheets, shows much importance for the various application in the field of biomedical, electrochemical, coating materials, catalyst, metal-matrix nanocomposite etc. To understand the processes involved, we have studied the atomistic behaviour of solidification, organizations and mechanical properties of silver nano-particle in the bulk and as well as in confined region by molecular dynamics simulations. In the bulk, silver nano-particle shows phase transition from liquid to crystalline phase at a temperature, T ≈ 1030 ± 25 K. However, in the confined region, silver nano-particle depicts the same phase transition at a relatively higher temperature. The tensile stress, initiation of cracks and subsequent detachment of silver during tensile deformation depends upon the temperature and interfacial interactions. The tuning of 12–6 Lennard Jones interaction potential energy parameter between graphene and silver (εAg-C) drastically influenced the phase transition of silver nano-particle in the confined region. At a high interaction potential energy (εAg-C), silver nano-particle shows good wettability over the graphene sheets and depicts the phase transition at a higher temperature compared to lower interaction potential energy.