Used to exist back on Microsoft's website, here, but unfortunately the link is dead and it isn't saved in the Wayback Machine.
There are several multilingual SP6a versions on the FTP, but sadly no arabic. sp6patch_i386.exe used to update NT from SP6 to SP6a is also fine as I already have SP6 installed.
EDIT: Interestingly enough, installing the arabic version of the post sp6a update (metq299444i.exe) before installing regular SP6a (en_us) doesn't seem to ruin the Windows install. The full executable is still appreciated though.
[REQ] Windows NT SP6a Arabic Ed.
Forum rules
Please read the following rules before posting a download request in this area:
1. Don't post a request if you have under 10 posts as stated in the rules. If you do anyway, it will be deleted without further notice.
2. Requests for anything against our rules will not be entertained and you will be warned.
3. Check that we don't already have the file on our FTP servers by using the database linked in the navigation.
Please read the following rules before posting a download request in this area:
1. Don't post a request if you have under 10 posts as stated in the rules. If you do anyway, it will be deleted without further notice.
2. Requests for anything against our rules will not be entertained and you will be warned.
3. Check that we don't already have the file on our FTP servers by using the database linked in the navigation.