Structural and magnetic properties of a two-dimensional spin-52 triangular lattice antiferromagnet NH₄Fe(PO₃F)₂ Fe³ explored via x-ray diffraction, magnetic susceptibility, high-field magnetization, heat capacity, and P31 nuclear magnetic resonance experiments on a polycrystalline sample. The compound portrays distorted triangular units of the Fe3+ ions with anisotropic bond lengths. The magnetic susceptibility shows a broad maximum around (Formula presented.), mimicking the short-range antiferromagnetic order of a low-dimensional spin system. It shows the onset of a magnetic ordering at (Formula presented.), setting the frustration ratio of at (Formula presented.)setting the frustration ratio of (Formula presented.) Such a value of f reflects moderate magnetic frustration in the compound. The dM/dH versus H plots of the low-temperature magnetic isotherms exhibit a sharp peak at HSF≃1.45T, indicating a field-induced spin-flop transition and a small magnetic anisotropy. Despite a tiny anisotropy, the magnetic susceptibility and NMR shift could be modeled assuming the spin-5/2 isotropic triangular lattice model and the average value of the exchange coupling is estimated to be (Formula presented.) This value of the exchange coupling is reproduced well from the saturation field of the pulse field data. The rectangular shape of the P31 NMR spectra below TN unfolds that the ordering is a commensurate antiferromagnetic type. Three distinct phase regimes are clearly discerned in the H-T phase diagram, redolent of a frustrated magnet with in-plane (XY-type) anisotropy.