selling rights

I wish to sell part of my rights entitlement but not sure how this is done. I assume Im supposed to have a SRN that I give to my broker (Etrade) and sell normally? I've not received any kind of SRN as of yet - is this because the record date is 12 Oct? If this is the case Im puzzled why people are already selling rights before this date.

Any help on this would be greatly appreciated.

Cheers, GJ