The field of nuclear physics can gain considerably from the developments taking place in the vast field of classical dynamics for non-linear systems. It is now realized that non-linearity in nature is the order of the day rather than an exception. Nuclear physics provides an ideal testing ground for the new ideas and results and remainslargely untouched by the "new physics". For the past 12 years, I have been focusing on research on theoretical nuclear physics. In this work, I have discusssed the possible impacts and a few recent applications of semiclassical techniques to understand "Nuclear Structure and Reaction Dynamics" together with appropriate symmetries. These techniques based on the periodic orbit theory (POT) have proved to be powerful tools for explaining the recently observed nuclear phenomena, which lie near the border of order and chaos. Mainly the work include the Semiclassics of Nuclear Fission, Nuclear Fusion, Periodic orbit theory and Single Particle Spectrum ofa particle (Semiclassical Shell Model), Chirality of Nuclear Rotation and Wobbling Mode in Nuclei.