Optimization of drilling parameters in Glass Fiber Reinforced Thermoplastic composites (GFRTP) has been analyzed using grey relational analysis in this research. The goal of this thesis was to investigate the effect of drilling parameters on composites of Glass Fiber Reinforced Thermoplastic composites (GFRTP) using hand layup method. The circularity and surface roughness are diminished. In drilling, tests were carried out on Glass Fiber Reinforced Thermoplastic composites with HSS drill bits of 6 mm, 7 mm and 8 mm diameter used in dry conditions using the Taguchi L9 orthogonal array process. ANOVA analysed the effecton output parameters such as surface roughness and circularity of multiple drilling input parameters such as cutting speed, feed, and cutting depth. For finding the best machining state, Grey relational analysis equations were used. For the drilling of hybrid Glass Fiber Reinforced Thermoplastic composites, the most critical parameter, namely the cutting speed, was found to have affected the thrust power, circularity and surface roughness.