How Bot based on Rasa respond to utterances other than data provided in data.json file

I have trained my bot with data creating using chatito , where I have created maximum possible utterances and data, but still its not responding for similar utterance For example , In greet intent I have used every possibilities except “Hi”, and when I am trying with "Hi " , It is showing no response or default message.

which nlu pipeline do you use?


but is the intent classification fo Hi wrong, is just the confidence is low?