u should not hav registered unsatisfactory branch........anyway now since u r alloted to ur last option,better u join that and wait for the further allotments...nothin is to be done,the upgradation takes place in further allotments and u will be considered on the basis of ur rank.....
And if u have a backup plan then if u don't get ur desired branch then u could cancel admission and u will get the refund(in the nxt financial year)... :)