The Indians used the No 4 for their first grenade launching rifles that used the Energa 22 mm grenades. Later they introduced a spigot launcher for the N1 MK III, though based on Jac Wellers 1964 article on the topic it was after 1963.
India captured a lot of No4 rifles from Pakistan in the 1965 war.
They also issued them to police, though I am not sure about the time period.
The latest rebuilt I have seen was a July 1973 rebuild of a No 4 MK I, the serial corresponding to a 1945 Fazakerely.
I have seen No4 replacement stocks dated as late as RFI 77, which by that time would likely be police issue only.