It's likely a misspelling or a variation of a name.
Here are some possibilities:
* Monta could be a shortened version of Montana, a state in the USA.
* Montae could be a unique name, potentially with personal significance to the individual who uses it.
* Montae might be a surname with no specific meaning.
If you could provide more context, such as where you encountered the name, I might be able to give you a more accurate answer.