His mark was made in southern Asia (7)
I believe the answer is:
kashmir
'made in southern asia' is the definition.
The answer and definition can be both locations as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'his mark' is the wordplay.
'his mark' anagrams to 'KASHMIR'.
Though, I am not sure how the anagram is indicated.
'was' acts as a link.
Can you help me to learn more?
(Other definitions for kashmir that I've seen before include "Subcontinental border region" , "State" , "Himalayan region" , "Disputed region between Pakistan and India" , "Territory disputed between India and Pakistan since 1947" .)