Perhaps Indian Mutiny's leader imprisoned in end (5)
I believe the answer is:
tamil
'perhaps indian' is the definition.
(I've seen this before)
'mutiny's leader imprisoned in end' is the wordplay.
'leader' suggests taking the first letters.
'imprisoned in' means one lot of letters goes inside another.
'end' becomes 'tail' (tail is a kind of end).
The first letter of 'mutinys' is 'm'.
'm' inserted into 'tail' is 'TAMIL'.
(Other definitions for tamil that I've seen before include "Member of South Indian people" , "South Indian people or language" , "Perhaps Indian" , "Southern Indian language" , "An official language of Sri Lanka" .)