Many of the contents provided by NHK are based on the premise of a viewing contract. They are for subscribers only. However, this does not assume a viewing contract.
Radio companies broadcast their programs for free in general. Besides TV programs, NHK provides online radio programs for three channels. It also provides a dedicated mobile free application.
If you do not have a viewing contract with NHK and watch TV via the network, using TVer, you can watch all for free, but in Japanese only, to see what is being shown. Try it with your OCR translator to sign up and enjoy local Japanese programs such as comedies, dramas, and animation films.
Lastly, all these services are available only in Japan unless you use the appropriate VPN service outside of Japan.