Hi I am a U.S. citizen. My sister is in USA for HB4 visa. If I file green card , can she stay back in USA after filing till she gets green card.

Unfortunately not. USCIS does not allow individuals to remain in the US just on the basis of a filed petition. You would be filing under the F-4 category for siblings of US citizens. For most of the world except for India and the Philippines which have longer backlogs, the availability date is only for those for whom petitions were filed prior to April 1, 2008. This is a backlog of approximately 17 years. Your sister would have to maintain nonimmigrant status to remain legally in the US. Due to the limitations of the Lawyers.com Forums, Alan Lee & Arthur Lee, Esqs.’ (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.