In a criminal case what would be the process for a juror that knew the victims family personally but assured the judge it wouldnt affect his verdictai

Did the defendant object to the juror being empaneled?  If not, he/she has probably waived his/her right to object now.  If so, however, and the Judge overruled the objection, the defendant can appeal his/her conviction.  Also, the new evidence discovered after the trial (the juror seen consoling members of the victim's family) might be a basis to vacate the judgment without need of an appeal, but I'm not confident that argument would succeed.