How long do I have to wait to get nvc after I get my parents' immigration 797 form?

After receiving the 797 approval letter, the payment notice will be given 30-45 days, and then DS-26 1 and DS-260 will be filled in, and the economic guarantee materials and notarial certificate will be prepared. After submitting the materials, the bill will be signed to P4 1 1 week. At present, it takes about 4-6 months from the receipt of P2 to the interview. You can start preparing economic guarantee materials.