The transition from NEW to RUNNABLE is obtained by calling the start() method. In this state, a thread can be running or ready to run. When it is ready to run, a thread is waiting for the JVM thread-scheduler to allocate the needed resources and time to run to it. As soon as the processor is available, the thread-scheduler will run the thread.

The following snippet of code should print RUNNABLE, since we print the state of the thread after calling start(). But because of thread-scheduler internal mechanisms, this is not guaranteed:

public class RunnableThread {

  public void runnableThread() {
    Thread t = new Thread(() -> {});
    t.start();

    // RUNNABLE
    System.out.println("RunnableThread : " + t.getState()); 
 }
}

RunnableThread rt = new RunnableThread();
rt.runnableThread();