Use the Anti-aliasing settings in the Render Options pane to use and configure anti-aliasing when rendering the camera image.

You should remove the grid from your current camera when using anti-aliasing because anti-aliasing is applied to the grid as well as to models.

You should also hide objects such as Nulls, lights, cameras, and skeletons. These objects are also anti-aliased when anti-aliasing is activated, and slow the frame rate and rendering time of your scene.