It's remarkable that so many journalists don't know that the 9/11 Commission Report found that 8 of 10 hijackers (not 10 of 12, it's true) traveled through Iran with the help Iranian government. Their passports were not stamped.
The idea that sunni terrorists were traveling through Iran without the knowledge and help of higher ups is around zero %.
In any event, Pence doesn't say that Iran helped or knew that those terrorists were planning 9-11, he merely says that Iran helped them travel to Afghanistan. That is almost surely true.
* 8 to 10 not 8 or 10
