The sixth level is called the "Manifest" because the Bodhisattva clearly perceives the workings of dependent arising and directly understands "signlessness" (Animitta), not only through a mental appreciation.
Signlessness refers to the fact that phenomena seem to possess their apparent qualities by way of their own nature, but when one examines this appearance one realizes that all qualities are merely mentally imputed and not a part of the nature of the objects they appear to characterize.
As a result of these understandings, Bodhisattvas manifest an avoidance of attachment to either existence or non-existence.
Thus they understand and operate correctly within Samsara, understanding the Two Truths and the delusion of Identity Truths.
Now we come to a complex point.
It is said that Bodhisattvas on this level can attain nirvana, but because of the force of the mind of Awakening (bodhicitta) they decide to remain in the world in order to benefit other sentient beings.
Let us get to the truth of this statement.
There can actually be an experience of Awakening at this level, but it is incomplete, because Identity factors have not be destroyed and the Nirvana effect is not lasting. What has been developed is the idea to withhold deep attempts to attain an Awakening, for in and of itself that act contains Identity intention.
Instead one cultivates the motivation to help all other human creatures first... This automatically sets Identity Awakening aside and the result is that Awakening arrives by itself when the Contemplations are correct and well-developed.
That means that while one can reach through Contemplations the experiences of Function, Essence and Undifferentiated Form, one will continue dwelling in those states without a natural advance to Awakening until "the other-directed impulse" is fully developed.
The Motivating Factor here is the cultivation of the Perfection of Wisdom, through which they perceive all phenomena as lacking inherent existence, as being like dreams, illusions, reflections, or magically created objects. All notions of "I" and "other" are transcended, along with conceptions of "existence" and "non-existence."
These sixth-level Bodhisattvas then abide in contemplation of suchness, with minds that are undisturbed by false ideas.