The study examines the effectiveness of Active Inhibitory Re-Stabilization (AIR) intervention compared to passive stretching in improving hamstring flexibility in college students with hamstring tightness. The study adopts a three-arm parallel-group randomized controlled design, involving college students aged 18 to 25 years who exhibit positive results on the Active Knee Extension (AKE) test, indicating hamstring tightness. Participants are randomly divided into three groups: Group A receives the AIR technique, Group B undergoes passive stretching, and Group C serves as a control group with no intervention. The AIR technique involves an active approach, where participants sit with a neutral spine and pelvis, extend their knee until resistance is felt, and then actively tilt the pelvis anteriorly while the therapist supports the leg. This stretch is held for 30 seconds and repeated five times per session, three sessions per week over two weeks. In contrast, the passive stretching group performs therapist-assisted stretches while lying supine, with the stretch similarly held for 30 seconds and repeated five times per session, also over two weeks. In that intervention, one session is given for one day, with alternate sessions on three days per week for two weeks. The control group does not receive any intervention and continues with their normal routine. The primary outcome measure used to assess the effectiveness of both interventions is the Active Knee Extension (AKE) test, which evaluates hamstring flexibility by measuring active knee extension using a universal goniometer. Measurements are taken before and after the two-week intervention period. The study aims to determine whether the AIR technique provides superior improvements in hamstring flexibility compared to passive stretching and no intervention.