Add the bin for every parent item using item import by updating item bin numbers for the corresponding parent item records external id.
The template for item record is saved as coma delimited file and go to netsuite> setup> import/ export> import csv records
Select import type as> items
Record type as inventory item
CSV column delimiter as Comma
Select the file to upload
Click next
Update>next
Do the required field mapping for item records
Next> give a import name and save and run
We can view the status by clicking job index status