* Collection of jigsaw puzzles
* Set of jigsaw puzzles
* Assortment of jigsaw puzzles
You could also use a more descriptive phrase depending on the context, such as:
* A pile of jigsaw puzzles
* A box of jigsaw puzzles
* A stack of jigsaw puzzles
Ultimately, the best way to describe a group of jigsaw puzzles depends on the specific situation.