Right now, you have the HTML trying to find the images here:
http://saiacs.edu.in/images/

Easiest fix is to upload them to the images directory on your server.

Another option is that these images are in your theme's images folder. If that's the case, then you need to set the src of the img to this:
<?=$this->getThemePath()?>

so, for your Twitter icon, it would look like this in the HTML of your theme:
<img src="<?=$this->getThemePath()?>/images/twitter-32.png">

This is assuming you have an images directory inside your themes directory that has these images in them.

- - EDIT - - -

I should mention that <?=$this->getThemePath()?> is the short_tag form of this:
<?php echo $this->getThemePath(); ?>

If your server does not support short_tag's then you should use this instead:
<img src="<?php echo $this->getThemePath(); ?>/images/twitter-32.png">

If you're not sure, it's probably safer to use the longer form.