Indian Mutiny's leader imprisoned in end (5)
I believe the answer is:
tamil
'indian' is the definition.
(Tamil is an example)
'mutiny's leader imprisoned in end' is the wordplay.
'leader' suggests taking the first letters.
'imprisoned in' is an insertion indicator.
'end' becomes 'tail' (tail is a kind of end**).
The first letter of 'mutinys' is 'm'.
'm' put within 'tail' is 'TAMIL'.
(Other definitions for tamil that I've seen before include "Asian language" , "South Indian people or language" , "Language of southern India and Sri Lanka" , "One in race" , "Member of South Indian people" .)