I want to ask, my brother-in-law is an American citizen. What is the success rate of my parents' immigration?

Mr. Deng Wenchao, I hope my answer can help you!

American immigration law allows foreign citizens who are related to American citizens or permanent residents to immigrate to the United States, which is American relative immigration. There are two kinds of relative immigrants in the United States: unrestricted and quota-free, and limited with quota restrictions. The waiting time for relatives to immigrate varies from six months to twelve years, depending on the category, from paper application to visa approval. Once the immigration application is approved, the applicant must go through the immigration formalities in person at the American Consulate in Guangzhou within the specified time, and other immigration visas are also handled at the American Consulate in Guangzhou. If the kinship cannot be fully proved, the immigration application will be rejected.