RingCentral is owned by Poly, which is under the same umbrella company as Plantronics. With that in mind, the only headsets that have call control with RingCentral are Plantronics and Jabra headsets.
Keep in mind that any of our headsets will be able to work with RingCentral, you will just have to answer the phone at the computer. For many people, that is more than enough!
Update: We have had one Customer who has gotten call control with Leitner wireless headsets, however we can't count on this working forever or with every version of RingCentral. Just an FYI.