Hello Vishal,
when you are selling due to maximum profit, logistics reason or any other reason you set the minimum order quantity as this is ordered by customer (external party)
but when buying it is taken care by your purchasing team and you can control this factor. However we dont have an option to control minimum purchasing quantity from purchasing side.
However under Planning Procedure ------------>Planning Procedure, you can set a fixed lot size to control for how much quantity PR can be generated. but when converted to PO, you again have the flexibility to change PR to PO quantity as per your wish.
Regards
Leo