Hi @rsrinivasanhome,
Welcome to the Auth0 Community and sorry for the late reply.
You can restrict a token to be used only for specific resource such as your API or device by specifying different audiences. For that you can create two APIs in your Auth0 Dashboard, one for your backend API and one for your device service, then make different requests to the oath/token endpoint.
Additionally you can also check into configuring a logical API. For that you can look into this documentation or this Knowledge Article.
Hope this helped.
Thanks,
Remus