I have a site which have joomla 1.5 having virtuemart 1.1.4 where virtuemart is having many customizations. Also i have some other components but my main customization is in virtuemart so is this possible that i upgrade my joomla from 1.5 to 2.5 and also virtuemart work with it with all customization i did ?
No, It will not be a good idea to upgrade the joomla and virtuemart. There are lots of changes has been made in both joomla and virtuemart so it can create a lot of problem in case you upgrade these.