try

Formula: copy to clipboard
=IF(OR(INDEX(INDIRECT(Tab!$C$8&"!"&Tab!$C$8&"Table23"),3,2)="Y",INDEX(INDIRECT(Tab!$C$8&"!"&Tab!$C$8&"Table23"),3,2)="Yes"),"Yes","Not Yes")


the syntax for or is

=OR(condition1,condition2,conditionx,...,conditiony)