Magnetic frustration, the phenomenon of being unable to satisfy all magnetic interactions in a system, draws a lot of attention as it is the source of exotic behavior in many magnetic materials. Although it has been thoroughly studied in various groups of compounds, little progress has been made in its examination in the half-garnet lattice family, particularly terbium gallium garnet(TGG/Tb3Ga5O12). TGG hosts an array of magnetoelastic effects e.g.: anomalous acoustic Faraday effect and thermal Hall effect, the microscopic origin of which has not been experimentally investigated yet. Moreover, as it has a strongly frustrated lattice, a non-Kramers doublet groundstate and low-lying excited states within the bandwidth of acoustic phonons, so it strongly resembles the pyrochlore terbium titanate(Tb2Ti2O7). It is therefore a promising candidate for hosting an exotic magnetoelastic spin liquid phase, as recently observed in Tb2Ti2O7. We propose a detailed study of the low energy excitations of TGG, on IN5, to look for coupling of crystal field levels and acoustic phonons resulting in exotic magnetoelastic excitations and to propose a Hamiltonian describing magnetic interactions in TGG.