My OPT already ended recently - can I still enroll?

Possibly yes - it hangs on one date. Inside the 60-day grace period: we can still get you admitted and transfer your SEVIS before it closes (no work until CPT starts). Past the 60 days: there are still two known paths - reinstatement, or leaving and re-entering with a new I-20 - and our senior consultant runs those personally. What was your exact OPT end date?