Actually it's really hard for a tamilan to figure it out. Still many people did. And my friend is one among that, many people. (Discrete mathematics, 3 attempts)
Here are those lines,
ennai thottal un ullathai norukka mattiyo
என்னை தொட்டால் உன் உள்ளதை நொறுக்க மாட்டியோ!
(wont your soul crush wen you touch me)
ennai pola pennai pathu, mayanga mattiyo
என்னை போல் பெண்ணை பார்த்து , மயங்க மாட்டியோ!
(wont you be mesmerized when you see a girl like me)
kannil kannai pootivittal, sirikka mattiyo
கண்ணில் கண்ணை பூட்டிவிட்டால் , சிரிக்க மாட்டியோ!
(wont you smile, when our eyes make contact)
ennil unnai serthu vittal ottikka maattiyo
என்னில் உன்னை சேர்த்து விட்டால் ஓட்டிக்க மாட்டியோ
(wont you just stick to me if we come close)
After hearing and enjoying those lines, then i realized that it might be a marketing strategy to release this movie in tamil nadu.
Because people in tamilnadu doesn't like to watch a dubbed movie often. (source : myself).
So adding few lines of tamil in the song and releasing it might create a buzz like
"machi enna da ithu hindi paatu la tamil add panirukanuga?? weight da, tamil vazhga"
And this buzz will be there till the movie release. Also every one, who even doesn't understand Hindi will be humming like chammak chalo chalo, which makes them to watch the movie.
If this is true, its a good strategy to release a tamil dubbed hindi movie.
And please note, im not against any language, its my thought and i have shared it. If the reader happen to find anything wrong in this post, forgive.