You mean Bangla keyboard layout? or Bangla translation?

I also have trouble with ibus, my language is Vietnamese, and I see the SCIM input tool works very well on deepin.
You can try it, if it works with your language would be a great thing
Good luck
Link https: //tinothree.wordpress. Com / 2012/02/19 / writing-bengali-bangla-in-linux-using-avro /