I want to move slider on left side of slider-bar. However, selenium webdriver moves it to right side but it does not move to left side. I want to move slider to 25% of total
You need to first switch to the iframe it is contained in i.e.
after that you can perform slide using JavascriptExecutor:
((JavascriptExecutor) driver).executeScript("document.getElementsByTagName('span')[0].style.left='50%'"); // 50% or whatever you like to provide.