Hello @Chandra Mohan , your request is specific to Vision AI Developer Kit (how to stop\start the camera), therefore the best place to get help is here: https://visionaidevkitsupport.azurewebsites.net/
Please create an Issue in GitHub or connect via Gitter.
PS: Stoping and starting the camera should definitely be done using Azure IoT Hub Direct Method, you will just need to know what function on Vision AI Developer kit to call in your method.