On Solaris, /home is handled by default by the automounter. That means you cannot create a directory there even as root. if you don't need it, just disable the home automount by commenting out the
/home auto_home -nobrowse
line in the /etc/auto_master file.
.bashrc works the same way regardless of the OS. However, this file is bash specific so if you haven't set your login shell to be bash, modifying it would have no effect on it.