What is the nationality of last name Rinthalukay?

It's impossible to determine the nationality of someone based solely on their last name.

* Last names can be common across multiple countries. There's no guarantee that a specific name is unique to one nationality.

* Names can be adopted or changed. People can change their last names for various reasons, including marriage, migration, or cultural assimilation.

* "Rinthalukay" may not be a real last name. It's possible this is a fictional name or a misspelling.

To learn about someone's nationality, you would need additional information.