Unlike Bhookailasa, these dances were incredibly difficult to sync together. The Tamil version runs a minute less in length because the Hindi version extends the verses in the middle (and often changes the melody to a minor-key which changes the whole "fun" atmosphere of the song). This is why you'll notice the Tamil version periodically freezes and dims while the Hindi version does it's thing for a moment (and during those times I bring in the Hindi music for a moment as well). Another frustrating roadblock is that the Hindi version is at a slightly-different tempo at various points of the song, so I had to compress or extend the time as necessary to match it to the rhythm of the Tamil version. The key to note is that the Tamil version and its music were not altered at all (except for the pauses) while the Hindi version has been altered slightly.
After watching it closely, I am 99% convinced that every single frame was remade for the Hindi version. At first, many of the dance-only segments looked identical, but when I paid close attention I noticed in every case there are differences. The giveaways are usually differences in how the pyjama fan between the legs swings or rises when the dancers spin or twirl, and also helpful are differences in how high the arms are held and the tilt of the dancers head. Some examples (click image to view full size):
Vyjayanthimala's pyjama fan swinging to the left vs. to the right
Looking down vs. looking up and leg height differences
I caught a mistake! They went to the trouble of ensuring the man shown seated from behind was the same man shown close up in the beginning (frizzy hair in Tamil, matted hair in Hindi), but when this seated shot is shown a second time near the end they reversed the frames!
Teeth vs. no teeth
What the comparison also makes clear is that you are really missing out on some beautiful close up shots of Padmini and Vyjayanthimala if you don't see the Hindi version! Although the Hindi song itself in my opinion has the most whiny and annoying melody when it differs from the original.
But perhaps most remarkable of all is that Padmini and Vyjayanthimala were able to dance each version with such precision that it takes a frame-by-frame viewing to conclude each version was filmed separately!