I don't have an Idea Sim but i've tested it personally on my cousin's phone & it is working here in North. Please follow these simple steps to use free unlimited internet.
First of all, create a new connection setting in your phone as :
Name : TechForEarning
Apn : internet
Proxy : LEAVE BLANK
Port : LEAVE BLANK
Homepage : http://zo12.fma.fb.me.php.t9space.com
Save the setting as default and open your default browser. Other browsers will not work.
 So, if you are on Nokia Java, Go to Settings > Go to Address & enter above Homepage.
 For Symbian phones v 5, go to Internet (Browser) & wait till the page loads. You can also use Opera 12 for this trick but you'll have to paste homepage manually in the Address bar.
 For Android, Create settings as above and open Android browser or Opera 12, now copy the homepage from above and paste it in Android Browser's Url box or in Opera 12's Address box.
After the page loads, you'll see a url box in the page, enter your site you want to browse. I suggest you to use Opera 12 if you want to download also.
Use on Low balance, recommended is Re. 1, Follow all steps carefully to make this trick work properly.
If you have any queries, suggestions then comment below.
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