What role does TITA question's accuracy plays in the CAT score?I mean if all the TITA questions which are attepted are wrong, does it affect the overall percentile?

Ya it doesn't matter at all. You can also verify from CAT website in which they give the formula and process they use to calculate percentile.

So if a person scores all TITA questions wrong, it doesn't even matter right?

No, only the effective score counts for calculating percentile.

Yes, tita questions dont have any negative marks.