In this work, we report the synthesis, characterization, and catalytic evaluation of Ni–Cu–Zn ferrite using tragacanth gum as a biotemplate and metal nitrates as the metal source by the sol-gel method without using any organic chemicals. The sample is characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). The powder XRD analysis reveals the formation of cubic-phase ferrite MNPs with an average particle size of 20 nm. The magnetic analysis reveals that the Ni–Cu–Zn ferrite nanoparticles have ferromagnetic behavior at room temperature with a saturation magnetization of 52.76 emu/g. The catalytic activity of Ni–Cu–Zn ferrite MNPs is evaluated for the synthesis of 2,4,6,8,10,12-hexabenzyl-2,4,6,8,10,12-hexaazatetracyclo [5.5.0.05,9.03,11]dodecane (HBIW) under ultrasonic irradiation. Mild reaction conditions, short reaction times, the use of an economically convenient catalyst, and excellent product yields are the advantageous features of this method. The catalyst could be easily recycled and reused few times without a noticeable decrease in the catalytic activity.