After your simulation si ready you can render the agents using renderman, arnold, vray(maya only or stand alone). For each of these render engines there is a procedural that can be executed inside maya/houdini or with the stand alone renderer.
Usually the procedurals need an atoms cache and a json table with the definition of all the agent variations. But in maya, renderman and arnold can render directly all the agent groups, just set the render engine in the render settings and press render but the motion blur is not supported in this case.
To render with the motion blur and also with Vray you must create an atoms cache of your simulation. After you exported a cache you can use the atoms proxy node to render it.
Maya
From the Atoms menu create a proxy node: Atoms → Rendering → Create AtomsProxy Node
From the AtomsProxy node set the cache file (the yourCacheName.atoms file). The time node is automatically attached to the time input. If you wan offset the frame use the offsetFrame attribute. If you want use a specific variation json file instead use the one from the scene then set the json file inside the variation attribute.
At this point lanch the render and you've done
Houdini
In houdini you can use the atoms proxy node only to visualize a cache. To render the agents you must use an arnold or renderman procedural node. From the Atoms menu use the Create Renderman/Arnold procedural command. It creates the right node and set up all the correct parameters to render your cache.