250kt
ICAO
Depends on the class of airspace, all airspaces where visual separation is used has the restriction below 10000 feet. (class C and lower) In C and D airspace ATC can remove the restriction (since they should know if there is any affected visually separated traffic)
IRL
Depends on the legislation of each country but all deviations from ICAO should be published in the AIP ( I would bet for some of the early chapters of GEN)
Then there can of course be specific requirements (ATC or other) for a certain approach but then it should be on the plate.