My self Jay Maurya new to this community and also new to magento. One of the My client is using Magento customised by some other people . Please advice how to check that which theme is used . I have tried a lot after searching the net but not able to identify. The site Was designed in 2010 and it is non responsive. I have got the responsibility to make it responsive . If possible some one could be advice how to make it responsive . I have the full access to the site. (www.vaishnomotors.com)
@jay_maurya - Welcome to the Magento Community and glad to see your first topic on this forums.
Re : your question - i have checked the link given by you http://www.vaishnomotors.com/ and found that it have theme called "vaishnomotors" - It is custom theme not ready made theme.
I have also check Magento version of the website - Your website have very old Magento version which is 220.127.116.11
If you have full access of website then you can check install theme from the backend - here if the full reference link how to check theme and change theme - https://www.templatemonster.com/help/magento-how-to-switch-your-store-to-default-theme.html
Also if you want to make this theme responsive - then you really need to edit the css , you need add mobile device compatible css to existing theme - or you can create new theme for the same.
Note : As an active/regular community member - just giving my suggestion that update your website with latest version of Magento (Ex - Magento 2.2.X) - your website have very old version of magento which might cause you on security level as well . At least as of now update your magento version to 1.9.X.