in my own opinion, for now that bitcoin know as a cryptocurrency (online currency). there is no way to this to use like offline currency, first you need an internet to make transaction on bitcoin and second bitcoin is an online currency that you didnt hold or touch knor you have an internet. but who knows in the future hope they find ways to use it in offline currency in the future.
Offline Bitcoin is available, but internet connection is required to control it. So it literally loses the meaning of Bitcoin without internet, but physical Bitcoin can be used.