Indian city featured in obscure plan (7)
I believe the answer is:
diagram
'plan' is the definition.
(I've seen this before)
'indian city featured in obscure' is the wordplay.
'indian city' becomes 'agra' (I've seen this before).
'featured in' indicates putting letters inside.
'obscure' becomes 'dim' (both can mean dark).
'agra' put inside 'dim' is 'DIAGRAM'.
(Other definitions for diagram that I've seen before include "Simplified representation" , "Explanatory figure" , "Explanatory illustration" , "I'm a drag (anag)" , "Simple schematic" .)