BanglKB v2 is Bangla Typing Scripts for WordPress 3.3+ .
Its an updated version of the plugin http://wordpress.org/plugins/banglkb which is outdated and does not work properly on newer versions of WordPress.
Download the zip file and unzip and upload in wp-include/plugins folder.
Go to your dashboard and install it via plugin installer. Done.
You will see three new buttons (phonetic, provat, english) under comments area on the frondend & on the backend you will find similar three buttons when you create or edit posts and pages on TEXT mode.
Read more http://codebangla.com