Mood: The mood of the video appears to be romantic and melancholic, with a sense of longing. The theme seems to revolve around love, heartbreak, or yearning, given the title 'Rehna Tu' which translates to 'You Stay' or 'Stay with Me'. The expressions on the faces of the lead actors convey a sense of emotional depth.

Environment: The setting seems to be an urban or semi-urban area, possibly in India, given the architectural background and the attire of the actors. The man is dressed in a casual yet somewhat formal outfit, while the woman is in a more casual, summery dress, suggesting a relaxed or everyday setting.