You may be qualified to apply for a US green card through your parents, children, spouse, or siblings. Whether you can apply immediately or will have to wait depends upon the family relationship you share with the beneficiary. Immediate relatives of US citizens include parents, spouses, and unmarried children under 21. Immediate relatives may file residency petitions without delay
Other relatives, apart from "immediate relatives", must wait for an immigrant visa number to become available according to the following categories:
Wait times will vary according to the Visa Bulletin.