How to display indian rupee symbol?

Font fontRupee = FontFactory.GetFont("Arial", "?", true, 12);
Chunk chunkRupee = new Chunk(" ? 5410", font3);

It's never a good idea to store a Unicode character such as ? in your source code. Plenty of things can go wrong if you do so:

• Somebody can save the file using an encoding different from Unicode, for instance, the double-byte rupee character can be interpreted as two separate bytes representing two different characters.
• Even if your file is stored correctly, maybe your compiler will read it using the wrong encoding, interpreting the double-byte character as two separate characters.

From your code sample, it's evident that you're not familiar with the concept known as encoding. When creating a Font object, you pass the rupee symbol as encoding.

The correct way to achieve what you want looks like this:

BaseFont bf =
    BaseFont.CreateFont("c:/windows/fonts/arial.ttf",
                        BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
Font font = new Font(bf, 12);
Chunk chunkRupee = new Chunk(" \u20B9 5410", font3);

Note that there are two possible Unicode values for the Rupee symbol (source Wikipedia): \u20B9 is the value you're looking for; the alternative value is \u20A8 (which looks like this: ?).

I've tested this with arialuni.ttf and arial.ttf. Surprisingly MS Arial Unicode was only able to render ?; it couldn't render ?. Plain Arial was able to render both symbols. It's very important to check if the font you're using knows how to draw the symbol. If it doesn't, nothing will show up on your page.