Mum needing doctor when in Indian city (6)
I believe the answer is:
madras
'indian city' is the definition.
(I've seen this before)
'mum needing doctor when' is the wordplay.
'mum' becomes 'ma' ('ma' can be a synonym of 'mum').
'needing' means one lot of letters go next to another.
'doctor' becomes 'dr' ('Dr' can be a synonym of 'doctor'**).
'when' becomes 'as'.
'ma'+'dr'+'as'='MADRAS'
'in' acts as a link.
(Other definitions for madras that I've seen before include "city out East" , "Former name of Indian city and state" , "Hot type of curry" , "Tamil Nadu capital; a hottish curry" , "something hot?" .)