The RingCentral API allows to initiate a 2-legged RingOut call programmatically.
From the users perspective it will work in a similar way as the RingOut feature on the RingCentral Web Site (more details about RingOut feature can be found here).
The API accepts the phone number where caller wants to pick the call, the called party number and optionally a caller ID. More details and examples can be found in the RingCentral API documentation