NiBr₂ is a van der Waals multiferroic material that crystallizes in the CdCl₂ structure type, featuring a frustrated triangular lattice of Ni² ions. At ambient pressure, it undergoes two successive magnetic transitions to a collinear in-plane antiferromagnetic (AFM) state that emerges at T_N1 = 44 K, followed by an order-to-order transition at T_N2 = 23 K into an incommensurate helical AFM phase. In the helical phase, multiferroicity arises due to spin-lattice coupling and inverse Dzyaloshinskii-Moriya(iDMI) interactions. We present a study of the pressure-driven magnetism in NiBr₂ using AC magnetic susceptibility measurements up to 3 GPa complemented by first-principles calculations and Monte Carlo simulations. Our results reveal pressure stabilization of the collinear AFM phase with rapidly increasing T_N1 up to ~100 K at 3 GPa. In contrast, the helical antiferromagnet phase carrying the multiferroicity is instantly suppressed at a critical pressure pc of ~1 GPa. This transition signifies a pressure-induced enhancement in the competition between the strength of direct second-nearest-neighbor interlayer exchange interaction (J⊥2 ) and intralayer frustration. The dominance of J⊥2 under increasing pressure suppresses helical spin order, favoring a purely antiferromagnetic ground state, as confirmed by Monte Carlo simulations. To probe the interplay between magnetism and lattice effects, we performed temperature-dependent X-ray diffraction (3–300 K). We observed distinct changes in the a (a = b) and c lattice parameters, with the c-axis showing a sharp shift at T_N1 and T_N2, directly linked to the magnetic transitions. This highlights strong magneto-elastic coupling, where magnetic fluctuations influence the lattice structure across both magnetic transitions. Our findings highlight the role of pressure-driven exchange anisotropy in tuning the phase diagram of NiBr₂. These results position NiBr₂ as a promising platform for pressure-controlled quantum magnetism, offering insights into quantum criticality and emergent phases in low-dimensional van der Waals magnets.