NRL must issue Parramatta (and anybody else in the gun) a breach notice, particularising the nefarious conduct and proposing the proposed punishment. Recipients of such notices are then afforded time in which to respond. For breach notices thicker than the Yellow Pages, this process takes time.
After any response is submitted, the NRL CEO must consider it and decide whether to impose the penalty originally specified or a different penalty. Other options include deciding the alleged breach never happened, or deciding that a different breach might have occurred (in which case the process starts afresh).
Now, assume the penalty specified in a breach notice constitutes the sun rising on Whacking Day for the Eels, and that Todd Greenberg remains resolute in imposing the proposed sanctions even after receiving Parramatta's response. What the club can do is request that any determination as to guilt or penalty be reviewed by the NRL Appeals Committee, chaired by former High Court Justice Ian Callinan, QC. The caveat is that, if four or less competition points are deducted, there is no right of appeal.
Such a review may proceed if Callinan decides that Parramatta's case is made on "plausible" grounds, or if there's any other good reason why the Appeals Committee should hear it. If the appeal proceeds, the club could appeal on the basis that Greenberg's decision was unreasonable; unsupported by the evidence; or because the punishment is manifestly excessive.
