How to set up a combined quantity total in a products order form?

So we want to allow up to 6 premium tickets to be purchased over multiple nights. 

Then they can add an unlimited number of GA tickets to the order. 

How can I set a limit so that the premium tickets have a combined quantity total of 6? 

Thanks!

I can see that you have already put a quantity limit up to 6 tickets per product. 

So the user can purchase up to 6 tickets for each of the first 3 products, is that what you are referring to? Or is up to 6 total for all 3 products? Example:

Unfortunately, that would not be possible since we do not have such a feature in our payment integrations.