They can form 9 rows with 6 students in each row.
They can form 54 rows with 1 student in each row.
They can form 27 rows with 2 students in each row.
They can form 18 rows with 3 students in each row.
This is because all of these numbers are factors of 54.
54 = 1 x 54, 2 x 27, 3 x 18, or 6 x 9.