Rank is all one has (6)
I believe the answer is:
estate
I believe this clue is a double definition.
'rank' is the first definition.
(I've seen this before)
'all one has' is the second definition.
(I've seen this before)
'is' is the link.
(Other definitions for estate that I've seen before include "Area of landed property" , "All that one owns at death" , "Houses - car" , "Amount of land - type of car" , "Property - tea set (anag)" .)