Try quitting business that's banked in Asia (5)
I believe the answer is:
indus
'that's banked in asia' is the definition.
(Indian river - something with banks)
'try quitting business' is the wordplay.
'quitting' suggests deleting specific letters.
'business' becomes 'industry' (industry is a kind of business).
'industry' with 'try' taken out is 'INDUS'.
(Other definitions for indus that I've seen before include "River of India/Pakistan" , "Important river" , "Long river of Asia" , "banker" , "Major river of Pakistan" .)