Hi Ajish,
Proteus 7.8 is the latest version available in the market. It does not support Linux OS. If you are looking for free version you can download it from the link http://www.labcenter.com/download/prodemo_download.cfm#professional
and if looking for Full version you can download it from torrent sites * http://www.4shared.com/rar/9bJV0aqb/proteus_78_sp2.html
Thank You !!!