Relating to the centre of reorganised state (5)
I believe the answer is:
focal
'relating to the centre' is the definition.
(as in a focal point)
'of reorganised state' is the wordplay.
'reorganised' indicates anagramming the letters.
'state' becomes 'cal' (short for California).
'of' is an anagram of 'fo'.
'fo'+'cal'='FOCAL'
(Other definitions for focal that I've seen before include "-- Length, -- plane; -- point" , "Of the point of convergence" , "Relating to a central point of interest" , "Things are concentrated at such a point" , "Relating to point of concentration" .)