Learn English – What does “Per [person’s name]” mean

The trick to understanding this advert comes at the beginning:

Here’s introducing iDiva: Five Magazines in One

So the publisher is saying their magazine is the equivalent of five other magazines.

Also they are selling the first issue at a cut down introductory price:

At an introductory price of Rs 5 per copy

So, in their mind, the magazine is cheap even compared to a normal magazine, but because it is five magazines in one, the cheapness is exaggerated by that multiple, so this deal is five times better than any normal discount on a magazine, i.e. five times over.

"off the top" in general and here means the first 5 hours

In "off the top of my head" it means the first idea that came into my mind. Similar principle