Here are some possibilities:
* "Grats" is a slang abbreviation for "congratulations." It's possible that "gratsy" is a misspelling of this term.
* "Gratitude" might be a possible origin. It's conceivable that "gratsy" is a shortened, informal version of "gratitude." However, this is unlikely, as it is not a commonly used word.
Without more context, it's difficult to determine the exact meaning of "gratsy." If you provide the sentence or conversation where you encountered this word, I might be able to help you better understand its intended meaning.