How long does it take USCIS to process the EB-5 applications of Iranian nationals?

The best way is to check the currently posted processing times for IPO on the USCIS website. If your case is beyond the current processing times, your attorney should inquire with IPO by email to get an update. It is not possible to know whether a delay is related to your nationality or other issues, such as any issues with your EB-5 project, your source of funds, or anything else unless USCIS issues a request for evidence.

As an Iranian national on an F-1 Student visa, it appears you filed your I-526 petition in 2015 but have not yet approved your approval. Typically, it is taking at least 14-18 months so you should receive a decision on your I-526 petition within the next 6 months or so. I would not think that you are experiencing any delay because of your nationality. However, once the petition is approved, you will want to file for Adjustment of Status to change your status in the U.S. Under no circumstances should you depart the U.S. to apply for an immigrant visa abroad.

While USCIS IPO processing times is showing November 22, 2015 as the current processing date, we see huge variations. At the same time, you should be expecting to hear soon, especially if other investors in the same project have approvals. Your place of birth, however, presents new and challenging issues. You may want to talk to your lawyer and review the President's most recent executive order regarding Iranian nationals; it bars all immigrant and most nonimmigrant visas.

Not at this stage unless your project or your source of funds is problematic. Check the USCIS website to see what date they are working on and, if they are past your date, regularly inquire.

Current processing time for I-526 is approximately 18 to 24 months from filing. Your Petition is not outside of the normal processing time at this point.

USCIS currently is processing I-526 petitions filed before 11/22/2015. Since your I-526 petition was filed before that date, it is likely with an officer and is being adjudicated. You can email the Immigrant Investor Program Office and ask for an update since your case is beyond the normal processing time. There is no way to know if the delay is related to your nationality or to some other issue regarding your petition, i.e. source of funds issue, or whether it simply is delayed due to USCIS backlog and processing issues.