iOS bangla text parser for web URL

In my iOS app i am sending a Bangla text to a method where i need to convert the text into format to convert into web link because the website can only read this types. How i can convert my NSString into this format ?

The url should look like :

%E0%A6%A7%E0%A6%BE%E0%A6%B0%E0%A7%8D%E0%A6%AE%E0%A6%BF%E0%A6%95/%E0%A6%A7%E0%A6%BE%E0%A6%B0%E0%A7%8D%E0%A6%AE%E0%A6%BF%E0%A6%95/%E0%A6%A7%E0%A6%BE%E0%A6%B0%E0%A7%8D%E0%A6%AE%E0%A6%BF%E0%A6%95/%E0%A6%A7%E0%A6%BE%E0%A6%B0%E0%A7%8D%E0%A6%AE%E0%A6%BF%E0%A6%95

In my code i did:

NSString *url=[NSString stringWithFormat:@"http://ift.tt/1EBPjZl",txt,txt];    

NSString *ss =[NSString stringWithContentsOfURL:[NSURL URLWithString:url] encoding:NSUTF8StringEncoding error:NULL];
NSLog(@"URL ::%@--%@",url,ss);

I am getting the direct URL only.

But it is not working in my way.

Any Solution ?