Do you want a genuine Windows 8 Pro license for a price of USD 14.99 (INR 699). Just wanted to tell you one things
Microsoft is not checking whether you are upgrading from a genuine Windows 7 or pirated one.
So if you want a genuine license of Windows 8
Step 1
Visit the Windows Upgrade Offer - Landing Page, select your country
Click Continue
While filling the form you need to take care few things
Date of purchase must be between 2 June 2012 and 31 January 2013
The last day to register and order your Windows 8 upgrade is 28 February 2013.
Brand, retailer details you can enter what ever you like.
Click Continue
You will receive a promotional code.
Step 2
Download Windows upgrade assistant and run it
when it ask for payment, at the last step before you make payment, you can enter the promotional key and the amount will be reduced (INR 699)
complete the installation (also you will get they key online)
Step 3
If you want a fresh install try this
Try this, it may expired soon 
Update
Now when you try to register for a new coupon code, it asks you for your Windows 7 Key and checks for the date when we activated it. If it was activated before June 2012, you won't get a coupon code. Now you will have to pay INR 1999.
Thanks @Ashwin