I see where the error is.
In the themes/classic/templates/_partials/javascript.tpl file the jquery is loaded in last few files. I just shifted it to up before all the js files are included in the same file and the price filter worked.
The error that I was getting in the console was $(...).slider is not a function
slider is a function of jquery ui , it must be loaded only after jquery, whereas in the default javascript.tpl file it was the opposite.