react-router v4 is base, building block. Provides API for creating routing solution.
react-router-dom is wrapper around react-router. It is supposed to be run in browser.
react-router-redux offers so called “controlled router”, bound to redux store. State changes (navigation) could be controlled by dispatching redux actions as well as by clicking on links.
Your best bet is to start with react-router-dom (which pulls in react-router for you by default).