You can't process GC for your parents until you are US citizen. Please visit:
http://uscis.gov/graphics/services/residency/family.htm#anchor365711.
People who want to become immigrants are classified into categories based on a preference system. The immediate relatives of U.S. citizens, which includes parents, spouses and unmarried children under the age of 21, do not have to wait for an immigrant visa number to become available once the visa petition filed for them is approved by the USCIS.
After you become a citizen and file I-130 for your parents, it takes about 1.5-2.5 yrs for them to get GC or immigration visa.
http://uscis.gov/graphics/services/residency/family.htm#anchor365711.
People who want to become immigrants are classified into categories based on a preference system. The immediate relatives of U.S. citizens, which includes parents, spouses and unmarried children under the age of 21, do not have to wait for an immigrant visa number to become available once the visa petition filed for them is approved by the USCIS.
After you become a citizen and file I-130 for your parents, it takes about 1.5-2.5 yrs for them to get GC or immigration visa.