it's a tongue-in-cheek misspelling of "congratulations" that's a play on the word graduate.
it means "congrats on ur graduations" :)
Sophie: i heard Mark succeeded in the senior year
Laura : yea, we have to send him our congradualtions
Jo : hey Steve, u made it man. way to go
Dave : Congradulations
Steve: thx guys, i wish ya the same