Observations from both iDPC experiments and DFT simulations reveal that perovskite octahedra need to tilt more at the central layers to accommodate closely positioned magnetic cations, signifying that octahedral tilting might play a crucial role in enabling long-range magnetic interactions and the resultant multiferroic behavior in B6TFMO. Our findings not only enhance the understanding of the naturally layered B6TFMO but also propel multiferroic materials science to the forefront. They highlight that engineering interfaces in heterostructures and layered materials presents a promising avenue for controlling material properties, marking transformative strides in multifunctional material design and application.