The western India-Eurasia collision zone (IECZ) has experienced devastating earthquakes in the past century and continues to be seismically active. However, the Stress regime and Seismotectonics of the region remains poorly understood. In view of this, we carried out iterative, joint stress inversions of 245 well-constrained earthquake focal mechanisms to constrain the stress regime and its spatial variability in the region and dwell upon their implications for earthquake generation. Salient new findings from the study are, (i) the Kangra-Chamba-Kishtwar region shows arc-oblique horizontal maximum compressive stress (sigma 1, WSW-ENE) in contrast to arc-normal (NNE-SSW) in other regions of the Himalaya, (ii) the Kashmir earthquake sequence (in 2005) and its epicentral region i.e. the Hazara Syntaxis show similar stress patterns with that of the Central Himalaya, (iii) Nanga Parbat Syntaxis experiences pure extension, and (iv) Kaurik Chango Rift, with N-S trending sigma 1, probably extends deep into the Karakoram fault. Based on these findings, we categorize the region into six state of stress fields consistent with geology and plate motion models. The magnitudes for these stress fields show a decreasing trend from 0.90 in the southeast (Garhwal-Kumaun-Shimla) to 0.46 in the northwest (Hazara Syntaxis) and 0.39 in the northeast (Karakoram) suggesting multiple tectonic forces in northwestern and northeastern regions. The study reveals heterogeneity in the stress field within the western IECZ, induced by tectonic forces and structural variability.