Laurent–According to Hoyem “The History and development of Small arms ammunition” Vol. 3, Page 109, the .410 India Police or .410 India Musket, was introduced in 1927. It does not say when it was discontinued, but does indicate that it was made until sometime after WW-II.
George Hoyem may be correct that it was introduced in 1927, but I do not know the source of this statement. The ball round was not formally approved until February 1929 in Paragraph A.445 in Indian Army Lists of Changes. The Buckshot load was approved in Para. A.1042 in June 1930, and I have a Kirkee loaded example of this date, the earliest I have seen. Other loads were approved soon afterwards.
I suspect that the round continues to be used today by Indian police, but have not seen any modern Indian or Pakistani rounds. Certainly Kynoch were still manufacturing the ball round in the mid-1950s on contract for either India or Pakistan, although they did not make any after that.
There are 3 examples coming up for sale in an ACCA auction next month.
They are a ball round with the h/s 410 I, a shot load with the h/s
K ^ F 410 I 30, and a blank with a 6 petal crimp h/s K ^ F 410 I 39
where ^ is a broad arrow