Hello,
It depends on the subject, if its an optional subject then mostly you might be able to get thru in revaluation. But do think of it like this, if you do pass in reval, it will get you an overall passing but with just an average score. But if you clear by giving the exam, you will have the chance to write the paper much better and much more focussed than before.
It will be a better way to increase your percentage.

This is my opinion, It might differ for you

All the best Soubhratra