Manas is an object, the visible “tip of the iceberg of chitta.” Mental vrttis refer to external objects. Mano vrtti nirodha is the gateway to chitta vrtti nirodha.
chitta vrtti
Meditation is Not Dhyana
Japa is a form of dhyana that everyone can do to nourish the subtle body. Manas is the “tip of the iceberg of chitta.” Dreamless sleep restrains manas (mind) but not the chitta vrttis.