my father who is u.s. citizen wants to file a petition for me ( f3 category ), but my sister already has filed a petition for me ( f4 category ),
so now whats is the procedure that my father has to undergo to file a petition for me that has the same priority date that of f4 previously filed ...
my petition ( under f3 category ) was filed by my sister in march 2004 (priority date ), by the time now my father has also become a citizen of usa,
now can my father convert the same petition under f3 with the same priority date?
and what will be the procedure to do so ?
please claear this...