Six lineages

The six lineages are:

1. the mind-direct lineage of the victorious ones,
2. the sign lineage of the vidyadharas,
3. the aural lineage of realized beings,
4. the lineage empowered by aspiration,
5. the lineage of prophetically declared succession, and
6. the dakini’s seal of entrustment lineage.

Also see three lineages of transmission.

Source

RigpaWiki:Six lineages