As the Chat GPT answer pasted below says, they're both okay grammatically. But I don't really agree with part about the meanings being different. To me, the biggest difference is that the first one with "on" is a more natural-sounding collocation. I think using "for" could sound also natural if you worded it like this: I'd like to congratulate everybody for having completed a very successful collaboration.

^^^ agree with *the* part ^^^

"On" is the preposition you use to put one object on top of another. It is used to LOCATE things: "Where is the cat? On the table." ("Where is the congratulation? On the collaboration.") "For" is the preposition you use to express purpose, relation, or intent: "What's the tool for? It's for fixing things", or "Where are you going? I'm bound for New York". ("Why are you congratulating us? For a successful collaboration.")

Both sentences are grammatically correct, but they have slightly different nuances. "I'd like to congratulate everybody on a very successful collaboration." This sentence suggests that you are congratulating people for their involvement or participation in the collaboration. "I'd like to congratulate everybody for a very successful collaboration." This sentence implies that you are congratulating people specifically for the successful outcome or result of the collaboration. Depending on the context and your intended emphasis, you can choose the one that fits your message better.