Hi gibes-anand
There are 2 installation types available based on your needs
1) You have already joomla installed on your website with another template
You should install only ja directory template.zip file via joomla installer and also other extensions listed ( without quickstart).
2) You need to install your website on your domain in a new installation ( your folder is empty, no joomla installed )
You will need to install ONLY quickstart and nothing else, ( quickstart install joomla + template + modules and plugins creating an exact replica of website as seen on our demo)
We provide a detailed documentation for both installation types at the url you posed above.
Regards