The Bengali India localedef file contained some minor error e.g. Tuesday and tue were written as ‘মঙগলবার’ and ‘মঙগল’ instead of ‘মঙ্গলবার’ and ‘মঙ্গল’.
The file has been modified and can be obtained from here. To use this in your system one has to follow the instructions from either here or here.
Also noticed another interesting thing in FC-5 [probably appilcable to earlier versions as well]. The text displayed on the “Previous” and “Forward” button in Firstboot are obtained from the gtk+ file. Hence the discrepancy in keyboard shortcuts and translated text.