Do indictments have to be prior-approved, or rather, can be negated like the report?

Indictments come from a grand jury, correct? Such that the g.jury already is standing, so if it reaches indictments, that's that? Did MUELLER have to get approval to enpanel a g. jury in the first place?

So this is separate from the court ordering to seal or not the indictments?

******As for the report, it would seem to defeat the purpose of an investigation if (DIS)APPROVAL from the Atty Gen or Acting or others might negate findings.