The music of Dilli 6 is out. This might be a bit too early to review a Rahman album plus being too lazy, may I point you to this review of Dilli 6 at Mitasha Muses :

A word of warning…at times the album brings out the unexpected with a flair, and that might not gel with everyone. For example, if you’re expected Mohit Chauhan to sing the kind of lovely smooth ballad that he has been singing in the last year…well, Masakali is nothing like that at all. If you’re willing to take the risk, you’ll be amazed at how sleazy and rebellious and bold he manages to sound in this number. Similarly, the title track is a little wild, not in the least because of the singers and the free use of digitalization, but its also very characteristic of Rahman (think Paathshaala). 

I liked the title track Dilli 6, which is an ode to the vibrant modern Delhi. But I still don’t think anyone can write a song better than the one by Rabbi Shergill.