According to Dow Jones News
The auto tariffs probe was launched in the last week of May and Ross has about 270 days or 9 months to finish up the report. So, I'm guessing he means that they may miss out on meeting certain deadlines to firm up the report.
The process will involve stuff like public hearings, consultations, and reviews on whether or not auto imports does have an impact towards national security. For some background of previous tariffs timeline, the steel and aluminium tariffs investigation/report took up the full 9 months.
