Rare-earth Iron garnets (RE3Fe5O12) have been in the focus of active research for the last five decades due to their fascinating properties, such as large magnetostriction, magneto-optical effects and possible application in spintronic. These compounds, model system illustrating the Neel theory of ferrimagnetism, has complex magnetic properties and influence of this complexity is not well studied. Hence, elaborate study of spin wave propagation on these ferrimagnetic insulator is required to provide microscopic models of its complexity. The proposed compound Ho3Fe5O12 can be a potential candidate for such type of study because of large anisotropy and strong magnetic moment of Ho3+ ion. No definitive work relating to the detail of magnon mode structure of Ho3Fe5O12 exists so far. Hence we are proposing here to perform INS in MAPS spectrometer to find out all the existing spin-wave mode.