They're made to be corrective (6)
I believe the answer is:
amends
'they're made' is the definition.
The definition suggests an adverb but the answer is not.
'be corrective' is the wordplay.
'be' becomes 'am'.
'corrective' becomes 'ends' (I can't explain this - if you can you should give a lot more credence to this answer).
'am'+'ends'='AMENDS'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for amends that I've seen before include "Changes for the better" , "Makes changes, to a text say" , "Alters and improves" , "Compensation" , "It is made in reparation" .)