"With" is the preposition that goes with "satisfied" generally, to govern the indirect object. "I was very satisfied with the result". "Satisfied with" would certainly be the most commonly heard but "satisfied at" would be perfectly acceptable and is what I would probably use.

Is it satisfied by or satisfied with?

Satisfied by occurs when satisfy is a verb in the passive voice: The conditions were satisfied by the new design. Satisfied with occurs when satisfied is an adjective meaning pleased or content: Only 19% of workers said they were satisfied with their jobs.

Do we say satisfied in?

"Satisfied in" is not a grammatical construction. Here's another example. If Sam is fed some food that fills him up but which isn't really very good quality, you might say that Sam (or more precisely, Sam's hunger) is satisfied by the food, and that Sam is not satisfied with the food.