Mountain lass found in area around Kolkata (6)
I believe the answer is:
bengal
'area around kolkata' is the definition.
(South Asian region)
'mountain lass' is the wordplay.
'mountain' becomes 'ben' (ben is a kind of mountain).
'lass' becomes 'gal' (both can mean a girl).
'ben'+'gal'='BENGAL'
'found in' acts as a link.
(Other definitions for bengal that I've seen before include "South Asian region" , "Bangle found in former Indian province" , "Bay of -- forms part of the Indian Ocean" , "found in part of subcontinent" , "Bay of --; -- tiger" .)