He or she can start the process the day after he or she arrives. But the judges cannot grant the citizenship letter until the second year. Meanwhile you are an informal argentine under the eyes of the law.Based on what Bajo-cero2 has perviously posted, applying for citizenship "right away"as a tourist doesn't appear to be an option. You may be able to start the process without "legal residency" (and with a lawyer) after one year, but it's apparently up to each judge whether or not to proceed with the case or make you wait until you have been in Argentina for two full years. Just come as a tourist, overstay that visa, and start the process after a year.