Lu and Yb counterparts of RE3Fe5O12 will be appropriate platform to reveal the complex magnetic ground state of rare earth iron garnets with common formula RE3Fe5O12. Lu3+ does not possess magnetic moment due to the absence of unpaired electrons with 4f14 electronic configuration, but Yb3+ possesses finite magnetic moment for having 4f13 ground state configuration. Hence, studying these two compounds together will explore the role of rare-earth moment in the magnetic ground state of these garnets. No definitive work on single crystal neutron diffraction study on these compounds has been performed so far. Hence, detailed study on magnetic ground states of these garnets is owed to plant to get insight into the fundamental physics and single crystal neutron diffraction is the best way to explicitly solve the magnetic structure of these compounds.