The final version of the documentation for Maya is still under construction. This temporary version is based on the Blender documentation, though its contents is relevant to Maya as well (both variants use the analogical UI).
Texel Density (Packing)
Certain texel density tools can be used in the context of packing. For example: you can make the packer automatically set texel density for the input islands before packing by enabling Set TD Before Packing.
All texel density tools are available in the Texel Density multi panel. Refer to the multi panel description to learn about texel density features in the context of packing.