Per Wikipedia:
Krittivasi Ramayan or Krittibasi Ramayan or Sri Ram Panchali, composed by 15th century Bengali poet Krittibas Ojha, is a translation of the Ramayana into Bengali.
Written in the traditional Ramayan Panchali form of Middle Bengali literature, the Krittivasi Ramayana is not just a rewording of the original Indian epic, but a vivid depiction of the society and culture of Bengal in the Middle Ages.
Is an English (or at least a Hindi) translation of the same available for free or for purchase?