What does Col stand for in Mexico?

It depends on the context, but I guess you mean as part of an address. That means it is a "Colonia" or neighborhood. For example, the American Embassy in Mexico City is on the "Cuahutemoc" neighborhood or colonia.

Mexico addresses include Street + number, Colonia, Zip Code, City, State, Country. For example:

American Embassy in Mexico City
Paseo de la Reforma 305, Col. Cuauhtemoc, 06500, Ciudad de Mexico, Distrito Federal, Mexico.
It depends on the context, but I guess you mean as part of an address. That means it is a "Colonia" or neighborhood. For example, the American Embassy in Mexico City is on the "Cuahutemoc" neighborhood or colonia.

Mexico addresses include Street + number, Colonia, Zip Code, City, State, Country. For example:

American Embassy in Mexico City
Paseo de la Reforma 305, Col. Cuauhtemoc, 06500, Ciudad de Mexico, Distrito Federal, Mexico.