So you want something like this --not exactly, I suspect, since I am not understanding the internals of the code, but this at least creates a list and computes a Mean:

Failed = 0;

Hit = 0;

NUMBER = 1000;

SetSharedVariable[Failed, Hit] 


N@Mean[Flatten@ParallelTable[x = Random[];
    ProbabilityStillGoing = (1 - \[Pi]/200)^j;
    If[ProbabilityStillGoing > x, Failed++, Hit++];
    If[Failed == Hit, j, {}],

    {j, 0, NUMBER}]
  ] 

What are you expecting this code to do?

Note (assuming you've given NUMBER a value) that the body of your ParallelTable command ends with a semicolon and there is a semicolon after the full ParallelTable expression. So (1) the table will contain all Nulls and the output of the calculation will be suppressed. The code runs, it just does not return anything. And the Print statements may or may not execute depending on the details of what's happening inside of the code.