a new tab of the same post/page opens whenever the stars are clicked for rating

You have errors in javascript (check the console in chrome). These are being caused by other plugins or the theme it self. You need to fix the js errors at first.

Surprisingly I tried to vote and it worked.

I voted here: https://www.bestonline.in/buy-fastrack-yellow-grey-backpack-a0310ngr01ae-at-rs-1276/