This work presents a comprehensive density functional theory (DFT) investigation of the nitrogen reduction reaction (NRR) on transition-metal (TM) atoms (Cr, Ni, Ru, Rh) supported on double nanorings (NRs = B₈N₈, B₈P₈, Al₈N₈, Al₈P₈, Ga₈N₈) via the distal pathway. The study focuses on elucidating the energetics, stability, and electronic properties of these TM-decorated nanorings as potential electrocatalysts for efficient nitrogen fixation. Geometry optimizations were performed using the long-range-corrected, range-separated functional ωB97XD combined with the polarized triple-ζ def2-TZVP basis set augmented with diffuse s and p functions. Interaction energies reveal that Ru@B₈N₈ is the most stable configuration, exhibiting a strong binding energy of −5.78 eV. Owing to this high stability, Ru@B₈N₈ was selected for detailed mechanistic evaluation of electrochemical NRR. A mixed-basics approach was employed in which Ru was treated using the LANL2DZ effective core potential, while B, N, and H atoms were described with the 6-31G(d,p) basis set to balance computational efficiency and accuracy. Charge-transfer interactions were analyzed using natural bond orbital (NBO) methods, and further insight into the electronic structure was obtained through frontier molecular orbital (FMO) and density of states (DOS) analyses, including evaluation of HOMO–LUMO energy gaps. Overall, this work provides fundamental insights into the stability and catalytic behavior of TM-supported double nanorings and offers valuable guidance for the rational design of robust and highly active NRR electrocatalysts.