Hi, what do you mean by not in sequence?
You can manipulate the BOM in different ways from the "Repeat Region" function in the Data group on the Table tab (given you are on Creo 1 or 2).
If you want to re-number items, you can achieve this with the Fix Index function, with this you can give a specific item the item number you want, and it will not change until it is manually unfixed.
You can also sort the region in forward or backwards sequence for any selected data column by the use of Sort Regions function.