In cities, oil refineries, and other sectors, gas pipes are used to transfer gases. Any damage to these pipelines causes leaks to occur later, which might have disastrous effects on both industry and the safety of the people involved. Therefore, it is crucial that this pipeline infrastructure be kept safe and maintained. The project "Robot for Under Pipeline Gas Leakage Detection" is suggested in this regard. It is suggested that a novel mobile robot move through pipelines, inspecting them for any damage that might be causing leaks. The mobile robot has an inbuilt ultrasonic sensor. This sensor is designed to measure the separation between the mobile robot and the obstruction (in this case, the pipeline walls), control the robot's movement, and locate the pipeline leak. When damage is detected, the mobile robot will halt at that spot, the sensor will identify the damaged pipe's location, and a buzzer will notify the administrator that a leak has been found. Additionally, the admin receives data from the Mobile Robot that includes the leak's location. The concentration of the gas inside the pipe is measured by the Gas Sensors MQ2 and MQ6. If the concentration is lower than the nominal value for that specific pipeline, we will know that the pipe is leaking, and the Ultrasonic Sensor will inform us of its location. The Atmega 328p microcontroller, which is integrated with all of the sensors, manages and synchronizes their operations and sends data from the mobile robot to the user.