You can activate Motion Blur from the Render Setup window or in Octane Camera.
Shutter Alignment - Specifies how the shutter interval is aligned to the current time. This determines when the camera shutter is triggered. The options are Before, Symmetrical, or After, and they apply to each frame thereafter relative to the given frame rate.
Shutter Time - This specifies the shutter time percentage relative to the duration of a single frame. Shutter Time controls how much time the shutter stays open. You can set this parameter to any value above 100%.
Motion Blur Duration is measured by frame duration. A value of 1.0 means Motion Blur Duration is equal to the frame duration.
Subframe Start/Subframe End - Specifies the approach, in terms of proportion (%) to simulate the camera’s shutter speed for that particular frame. OctaneRender uses Subframe Start and End percentages to render only a portion of a particular frame. If the scene has a lot of motion blur, OctaneRender uses these parameters to render only a piece of that motion blur. Values of 0% and 100% render the whole frame (default).
Every object with motion blur should enable Object Motion Blur in its Octane Properties.
If an object doesn’t have any deformation animation, you should enable Movable Proxy and Object Motion Blur. If you have fast curved objects moving, increase the Motion Blur steps. For object deformation animation, you should enable Movable Proxy and Vertex Motion Blur. Vertex Motion Blur ignores Motion Blur steps, and always uses 2 steps. This is a render engine limitation.