Flow through collapsible tubes holds significant physiological importance, which can be widely seen in our body, especially arteries, veins (thin-walled and highly adaptive blood vessels), vocal cords (behaves like an airline), urethra (acts as thin-walled elastic tube), pulmonary capillaries, etc., and finds widespread application in various industries as well. In this study, we focus on the dynamics of a thin collapsible tube subjected to internal airflow and its interaction with the surrounding fluid medium. The tube response exhibits varied oscillatory behavior across a range of Reynolds numbers (Re), showing bifurcating patterns. The free water surface also shows similar oscillatory features in response to the disturbances induced by the oscillations of the tube. Our research contributes valuable insights into the dynamics of a collapsible tube and its interaction with fluid flow, which could have far-reaching implications in physiological research and diverse industrial sectors such as petrochemical, pharmaceutical, nuclear engineering.