Depends.
They probably look at the first group that comes in and is downloaded from ERAS in September.
Residency is not like medical school. Every program does things differently, on a different time scale.
If you are asking if you can wait until October to submit your ERAS application, technically you can...but if you apply at the beginning of the application cycle, you may get earlier interviews (depending on the reason for delay of application).
See other thread here where applicant talks about waiting until Oct/Nov to apply last year and only getting 6 interviews (and presumably not matching) with applying in September and dramatically increasing his number of interviews.