Federal Rule of Civil Procedure 48
Rule 48. Number of Jurors; Verdict; Polling
(b) VERDICT. Unless the parties stipulate otherwise, the verdict must be unanimous and must be returned by a jury of at least 6 members.
(c) POLLING. After a verdict is returned but before the jury is discharged, the court must on a party’s request, or may on its own, poll the jurors individually. If the poll reveals a lack of unanimity or lack of assent by the number of jurors that the parties stipulated to, the court may direct the jury to deliberate further or may order a new trial.