If it is real, it looks like one of these coins, bearing the names of Ferdinand and Isabella obverse around the shield:
https://en.numista.com/catalogue/pieces32164.htmlhttps://en.numista.com/catalogue/pieces131232.htmlIf you rotate the first photo 180 degrees, you have a legend REX:ET:REGINA:CAST:LEGIO:A:S:G
It seems to match the second coin better (T could be for Toledo mint)
But the weight is far off from either, and there is a sort of grainy look to it that suggests cast, so maybe it could be a replica.