For some reason I keep coming across some Brazilian websites with .rs as well, but not sure why.
> some Brazilian websites with .rs as well
Brazil's currency is the "reais" and has the sign "R$"
To be very pedantic: Brazil's currency is "Real", plural "Reais". There was around a century ago an older Brazilian currency also called "Real", but with plural "Réis".
Maybe its because of people from the state of Rio Grande do Sul[1] - commonly shortened to RS