According to this G.O-
“… It is further clarified that it is applicable only for those who are enjoying the maternity leave on the date of issue of this order…”
So, according to my opinion, whose maternity leave is continue at the date (19/02/13) will avail leave 180 days i.e whose date of termination of maternity leave was on and after 19/02/2013 can enjoy 180 days leave. And for this she have to submit an application for extend her maternity leave to her M.C/V.E.C vide the said G.O no. and date.