This paper presents a comprehensive seismic performance evaluation of a G+15 reinforced concrete (RC) moment-resisting frame building located in Seismic Zone V of India, employing both Nonlinear Static (Pushover) Analysis and Nonlinear Dynamic Response Spectrum Analysis (RSA). The building, modelled in ETABS as a three-dimensional space frame, is designed as per IS 456:2000, IS 875 (Parts 1 & 2), and IS 1893:2016, with M30 concrete and Fe415/Fe345 steel reinforcement. Pushover analysis was performed in both the EQ-X and EQ-Y directions; the resulting capacity curves exhibited nearly linear elastic behavior throughout, with a maximum base shear of approximately 144,452 kN (X-direction) and global lateral stiffness values of 80.3 kN/mm (X) and 8,762 kN/mm (Y). The FEMA 440 Acceleration-Displacement Response Spectrum (ADRS) evaluation did not yield a performance point in either direction (ductility ratio μ = 1.0), confirming elastic structural response. Response spectrum analysis produced maximum roof displacements of 52 mm (RSX) and 118 mm (RSY) at Story 15, with maximum inter-storey drift ratios of 4×10⁻⁶ and 8×10⁻⁶ — approximately 500 times below the IS 1893:2016 permissible limit of 0.004. The results collectively demonstrate that the structure meets all performance-based design objectives as per FEMA 356 and ATC-40 guidelines, with substantial safety reserves against seismic demand. The combined application of both analytical methods is confirmed as a robust framework for comprehensive seismic performance assessment of tall RC buildings in high seismic zones.