Yes. The country you know as Mexico has a "federal representative republic" style of government. In fact, Mexico is the nickname of the United Mexican States, as it is known officially.
Se related questions for further explanation.
If you mean whether New Mexico is a republican or "red state", the answer is no: it has been mostly a democrat state for three of the last four elections.
If you mean whether the country of Mexico is a republic, yes, it is a federal presidential representative republic, just like the United States.
Mexico
Mexico is more democratic then it is republican. It is a republic though.
There are no countries in Mexico, Mexico is a country.
Mexico IS a country.
Mexico is a country, but the capital of Mexico is Mexico city.
In the country of Mexico.
A country. Mexico is part of North America.
Democratic
New Mexico has alternated between one Democratic governor and one Republican governor since 1983. In 2012, they're on Republican.
The country south of New Mexico is Mexico.
Mexico is a country
Mexico is a country.