There is only one country on the planet where you can legitimately make Tequila, and it is Mexico! Unlike vodka, gin, and rum that can be made anywhere, Tequila belongs to Mexico. The regions within Mexico where the product can be produced: Jalisco (includes the town of Tequila), 8 municipalities in Nayarit, 7 municipalities in Guanajuato, 30 municipalities in Michoacán, and 11 municipalities in Tamaulipas.
Tequila has a Mexican DOC (designation of origin) respected in 40+ countries and is protected through NAFTA in Canada and the US and through bilateral agreements with individual countries such Japan and Israel. It has been protected in the EU since 1997.