Natural disasters are increasing day by day as the climate crisis becomes more serious. In a disastrous situation, search and rescue missions are very risky, time-consuming, and resource constraints. A hybrid drone-assisted mixed reality-based system (termed as "MR-Drone") is proposed for conducting search and rescue operations very quickly and efficiently in a disastrous situation like an earthquake, floods, fire breakout, etc. In our proposed system, we use drone’s real-time steaming for generating a 3D map of the target area and this map can be shown in mixed reality device like HoloLens for monitoring the rescue mission. Multiple users can monitor the emergency together in a mixed reality environment using MR-Drone thus reduce the rescue time.