I'm trying to make a bluetooth keyboard(3x4)for Android Phones with the use of any arduino because I'm trying to make that as a Braille keyboard. Is it possible? If it is. What kind of arduino should I use? And any other bluetooth shield?
You need an Arduino uno (or any compatible board) and a bluetooth shield or board for Arduino. You can try out this bluetooth board from sparkfun.
This board connects to Arduino via serial. So you can just used the built-in Serial library.
This board also connects easily with Android devices.