Understanding the interaction between photons and matter is crucial for exploring essential questions in nuclear physics. The Giant Dipole Resonance (GDR) is the prevailing mechanism in photo-absorption cross-sections up to 30 MeV. Depending on whether the nucleus is spherical or deformed, the curve of the photo-absorption cross-section versus photon energy is characterized by one or several Lorentzian peaks. Theoretical calculations of photo-absorption cross-sections are largely centered on deducing GDR parameters. These parameters are used in theoretical reaction codes that aim to simulate photon-induced nuclear reactions accurately. In this study, the GDR parameters for the spherical isotopes 115In, 144Sm, 148Sm, 150Sm, and for the deformed isotopes 154Sm, 153Eu, and 160Gd were calculated by optimizing to the experimental data. The calculated GDR parameters were inputted into the TALYS 1.8 code to compute the photo-neutron cross sections, which were then compared with experimental results from the literature. It has been observed that the calculations performed with the obtained GDR parameters are consistent with the experimental data.