Note how the performer in this video holds his right hand against his abdomen, index finger out, while with his left hand he wiggles his fingers and pulls it up and away.
Is that a meaningful gesture in Indian culture (like the thumbs-up in the West), or is it just dancing?
That is just Punjabi Pop song /video from the 90s. Those gestures means nothing.
As far as I know, Punjab does not have classical dances or music (just folk dances / music - like Bhangra or Gidda)
In other parts of India - gestures in classical dances like the Bharatnatyam, Odishi, kathak, etc the gestures have meaning.
It’s not a meaningful gesture in Indian society generally. It might be something that Daler Mehndi thought looked cool. The chorus of that song is just nonsense syllables so far as I can tell.