Hi titos ,
Did you duplicated the collection before applying the preset on the collection first?
You could also use History panel in Lightroom to undo the editing done on your images.
Yes I did duplicated the collection before. But is it possible to have a picture in 2 collections, and both collections have different preset applied?
Seem I need to create a select all and virtual copy, then drag them into a new collection.
Yes, virtual copies are required to create multiple versions of an image.
Collections all refer to the same one image regardless of the number of collections the image is in.