In looking at Rivals, a realistic best case scenario would be for Notre Dame to pick up about 12 or 13 guys who are rated in Rivals top 250.
Of those 13, there will probably be;
4 linebackers
4 offensive linemen
2 running backs
Tyson Ford
Hopefully, a WR and/ or DB
I don't mention names specifically because Notre Dame seems to be in the running for several combinations of OL, LB, and RB prospects that they have a realistic shot at.
As far as WR and DB, they are in the running for a few guys in the top 250, but I don't feel as confident about those positions as a I do the others. That being said, there are still quite a few 4 Star players not in the top 250
that Notre Dame has a legitimate chance to land.