Hi Neha,
With all the information provided by you and above thread exchange we can only suggest you to have a look on your transaction history in the system using MB51 for the material.In this particular case without looking at system transaction history it is very difficult for any one of us to provide the actual reason for the difference however we can
think certain possible reason
1) Since you have three storage location. is this mismatch is in one particular location, if yes might be during initial stock upload team might have missed to update the same in WM or
2) initially the Sloc was only IM managed and later on they made it to WM managed but missed to take care of existing stock
if you are confident that these stock doesn't exist in warehouse and want to correct it then as suggested by Jurgen you can go ahead with LX23 to correct the same with approval from your organization senior management as addition or reduction of stock can have financial impact
