How to update Max Limit To Buy Products in Bulk?

To manage the minimum and maximum order quantity for products in bulk you can refer 
https://help.storehippo.com/topic/product-csv-file-format

To define the minimum and maximum quantity for users to purchase for a single product you can refer https://help.storehippo.com/topic/addedit-a-single-product 

If the product has multiple variants, then to manage minimum and maximum quantity you can refer 
https://help.storehippo.com/topic/options-and-variants