My requirement is to give edit permission for individual user to particular excel sheet. All other user can only view the sheet and all the sheets contains grouping. Kindly help in resolving this.
In 2003, Under Data - Protection, you can setup ranges which groups or individuals can edit. In 2007, it's just under the Data tab. Note that this method does require that you protect the worksheet.
I don't think you can keep the grouping AND protect your data. You could potentially use a VB Change event macro to detect changes on the other sheets and then reverse them, but that could get quite complicated.