If a parent of USC whose I-130 has been approved, case sent to NVC, then sent to US Consulate does not go for the Interview and does not avail the IV can avail it at a later stage? Your comments are appriciated.
If your parents do not avail the opportunity, given to them under the laws, that Petition will remain valid until one year from the date of notification last issued by the Consular Section of US Mission for one year. After that it will returned to the the USCIS.