https://en.numista.com/catalogue/pieces1295.html
It is a 2/6d (two shillings and sixpence) half crown coin from United Kingdom. It was made in 1947, the first year of cupro-nickel metal - the previous years were silver in part. Some places mention pre-47 coins wanted/for sale as they have more value merely for the metal content. There were four crowns to a pound (pre-decimal, so twenty shillings) or eight half crowns. They do look a bit like South African coins (as they had the same kings and queens on, for a while).
https://en.numista.com/catalogue/pieces14732.html
That is the similar South African coin - slight difference on lettering on both sides (especially the reverse, as it mentions South Africa). I notice also that they were later in changing from silver to cupro-nickel as they continued until 1960 I think.