The update was live since February 18th.
India ? Lumia Denim update now available for Lumia 525, 535, 620 and Lumia 720 | Windows Central
I don't know other models but I am using Lumia 620 pfd with lumia cyan my phone show your phone is up to date and my friends Lumia 620 pfd show your phone is up to date. I can't receive any updates. But MS say Lumia 620 already receive Lumia denim.
Turn off PFD, and you'll get updates.
Worked with my 525