While there have been many attempts to show that these are either the same or different, in my view that is missing the point somewhat. The terms are, generally speaking, synonyms, and their usage overlaps to some degree, but they tend to be used in different contexts:
- Viṇṇāṇa is part of the khandhas and āyatanas, and hence pertains to the first noble truth: it is suffering.
- Mano is typically used in an active sense of will or volition, closely related to kamma, and hence pertains to the second noble truth, the cause of suffering.
- Citta is to be developed and thus pertains to the fourth noble truth.
- The cessation of all these is, of course, the third noble truth.