However, here are some options depending on the context:
* Round: A round of drinks
* Selection: A selection of drinks
* Assortment: An assortment of drinks
* Variety: A variety of drinks
* Batch: A batch of cocktails
* Set: A set of cocktails
* Order: An order of drinks
You could also use more descriptive terms based on the type of drink:
* Flight: A flight of beers
* Tray: A tray of shots
* Barrel: A barrel of ale
* Pot: A pot of tea
Ultimately, the best collective noun to use depends on the specific situation.