In Dirty Dancing Havana Nights what is the name of song played in salsa club which also Along Came Polly The word CUBA chanted it?

The song you're looking for is "Chan Chan" by Buena Vista Social Club.

It's a popular Cuban song that's featured in both "Dirty Dancing: Havana Nights" and "Along Came Polly". You're right, the "CUBA" chant is a prominent feature in both films, making it easily recognizable.