arabic language support

Thank you for great job
I’m asking about the arabic language is not among selection

thank you

Are you sure? I have checked the download page and I found arabic selection ( ar-العربية) there. However you can check the download page:
http://www.libreoffice.org/download/

After you install LibreOffice, don’t forget to enable support for “Complex Text Layout” (CTL), otherwise you cannot type your Arabic text properly. Go to Tools → Options → Language Settings → Languages. Then check the box near “Enabled for complex text layout (CTL)”. Like this picture:

After you do this, you get two extra buttons in the formatting toolbar to switch between RTL and LTR.