How long does it take the NVC to receive an EB-5 case?

It means that USCIS and the NVC are very slow! This has been the case for some time and does not seem to be improving. Be patient and continue to inquire every 30 days or so.

We are seeing around 3-4 months for NVC to receive EB-5 cases.

The letter from the NVC is self-explanatory; it simply means that the NVC can neither do anything nor comment on your case until it receives your case file. Just make sure your file arrives at some point. Thus, while you may be concerned about the length of time this is taking, it is nothing unusual that transfer of case files between these two agencies takes some time. Just wait a little more.

Assuming visa numbers are available and you have an approved visa petition, the National Visa Center should receive your approved EB-5 investor petition on Form I-526 within a reasonable period of time; normally within a two-month period. It can vary depending upon the USCIS workload and a variety of other factors. If you do not receive a response, you should follow up with the USCIS directly or through your attorney or perhaps through a Congressional inquiry.

Lately we are seeing as much as a four-month time gap between the approval and when NVC receives the approval notice.

It routinely takes 2-3 months, sadly. No need for panic, yet.

It is taking more than two months to transfer the cases from USCIS to NVC these days and in some cases, much longer. Put in a request to USCIS also and keep asking.

It should not take 10 weeks. Check the approval notice if it says that they forwarded it to the NVC.