If you are an individual artist or student:

Version 6.3.1 was specifically updated to support 3ds Max 2021 and introduced official support for the Arnold renderer for the first time. The Quest for a "Free Download" Library

October 26, 2023 Subject: Feasibility, Legality, and Technical Context of Acquiring Forest Pack 6.3.1 Libraries

is a professional 3D scattering plugin for 3ds Max, developed by iToo Software. Version 6.3.1 is a commercial product that requires a valid license. Downloading it or its premium libraries from unauthorized "free download" sites typically involves: