Are called in to make preparations (7)
I believe the answer is:
arrange
'make preparations' is the definition.
'are called in' is the wordplay.
'called' becomes 'rang' ('ring' can be a synonym of 'call').
'in' indicates putting letters inside.
'are' enclosing 'rang' is 'ARRANGE'.
'to' is the link.
(Other definitions for arrange that I've seen before include "Put in order; make plans" , "Put in systematic order" , "Place in order" , "Organise, plan" , "Order, plan or design" .)