A localized magnetic field is a vector field that alters in space because of magnetic materials or electric currents. Some examples of localized magnetic fields are indoor localization, magnetic anomaly detection, magnetoencephalography, and quantum physics. Magnetic fields can be used to estimate the orientation and position of a device inside a building by measuring the changes in the magnetic field caused by ferromagnetic substances. On the other hand, a Tri-hybrid nanofluid can transfer heat better than a normal hybrid nanofluid by mixing three different nanoparticles with synergistic effects. It can have more varied physical and thermal properties by choosing different combinations of nanoparticles. That's why it has more possible uses in various fields such as solar thermal, biomedical, and industrial processes. Therefore, the goal of this research is to explore the complex dynamics of the localized magnetized force that affects the rotation of nanostructures and the vortex formation in the tri-hybrid nanofluid flow regime using the single-phase model, while the governing partial differential equations are discretized numerically. With the help of our self-developed computer codes in MATLAB language, we intend to understand the way these parameters affect the flow and thermal properties of the nanofluids. Additionally, the current work provides a novel analysis that makes it possible to investigate the flow lines and isotherms associated with the magnetic strips inside a flow field. It is discovered that the spinning of tri-hybrid nano-particles, which creates the intricate structure of vortices inside the flow regime, results from the magnetized field. Further, the investigations reveal that both the local skin friction (CfRe) and the Nusselt number (Nu) increased by up to 46% and 99% when the magnetic field is strengthened. Finally, adding more nanosized particles in the flow field result in increased both Nu and CfRe, but differently for different nanoparticles. Silver (Ag) had the highest increase in both Nu (55%) and CfRe (110%), showing strong thermal-fluid coupling. Alumina Al2O3 and Titanium Dioxide (TiO2) had lower increases in both Nu (33% and 25%) and CfRe (13% and 9%), showing weaker coupling in the flow regime.