Yes, you may mark various stock items based on its usage by selecting the relevant usage type. To do so follow the steps given below: –
1. Edit the item in Stock Master
2. Click on “F7: Save”
3. GST Details window shall appear.
4. Click on “Advanced Columns” check box
5. Column “Usage Type” shall appear in entry window (see pic 1).

If nothing is mentioned in “Usage Type”, it is assumed that item is used / supplied exclusively for business.
In case of exempted goods, it is assumed that goods are used in supply/manufacturing of exempted goods.