If you have a detailed scan of a tree in e57 format you would first need to filter and generate a mesh of the trees structure. This can be done in most of the scanning processing software that comes with terrestrial scanning systems Trimble, Leica, Topcon, Faro, Z&F.
Once you have a mesh generated to the detail you desire you will need to export it as an OBJ or Collada DAE file format.
These two formats can then be imported into a File Geodatabase as a Multipatch. you will then need to scale and place the feature in the correct spatial location using "Move" and "Scale" tools in Pro.
You may also just import the e57 point cloud into ArcGIS as a LAS file and geolocate it in the correct location maintaining all of the information (intensity, RGB, points) captured in the scan.
