Yep - 5.7.1 is the last 32 bit version.
The real question is "Can your system run a 64bit operating system and if it can why are you still stuck on using a 32bit OS"?
Yes that is true , Lightroom 6 is for 64 bit version.
Its a good idea to upgrade your OS(make sure the processor support that)
Thanks to all of you. Discouraging but I guess that's the way it is for now. The system can't handle anything else.