WooCommerce Min Max Quantities:
WooCommerce Min Max Quantities is a little yet very simple solution for the store manager. The manager can restrict quantities per product that the customer can purchase. If you do not want your customer to purchase more than X quantity. For the reason, you can simply fix maximum quantities in the backend. The customer then cannot purchase the product above the fixed quantity. If they will try to purchase, this extension will give an error message during cart/ checkout. It will also inform them of the criteria they need to meet before they can continue.
A similar way you can restrict them to minimum quantities per product or groups and all these parameters can also be used with product variations.