Here are a few ways to translate it, depending on the context:
* As a name: You could use "Gran" (pronounced "grahn") which is the Spanish word for "large" or "great". It's not an exact translation, but it conveys a similar feeling.
* As a surname: You could use "Granado" which is a Spanish surname meaning "from a pomegranate orchard". While not directly related to Grant, it has a similar sound and feel.
* As a verb: If "Grant" is used as a verb meaning "to give" or "to allow", the Spanish equivalent is "Otorgar".
Ultimately, the best translation would depend on the specific context and the intended meaning.