@prachi you're mixing client side code and server side code. I believe you're also using a sample I had provided on how to group items which was a client side sample. You've taken that client side sample and just pasted it into a server side after submit script. So any nlapiGetLineItemValue calls aren't going to work and need to be changed to irObj.getLineItemValue. Also In your context I would recommend performing the group action on it's own. Right now your doing the item group action for every row in the sublist, so ten lines in the sublist means you un-necessarily performing the group operation ten times, the remove line item call that was part of the client side sample I provided also isn't necessary either as your not actually updating the sublist which was part of your original question a week or so ago. I will DM you to try and help you out some more.