@Neeraj You can trigger the message from Rasa with the dummy message when the user first starts the chat, which runs a custom action to check the user’s location and send the appropriate message based on the time.
So you’d send something like below from the client when the user joins:
{
"sender": "<some_id>"
"message": "/greet"
}
which would trigger this story in Rasa:
## Greet user by location
* greet
- location_based_welcome
And the location_based_welcome would be a custom action that determines the appropriate response. See these docs for more info.