The Mahabharata Epic in Bengali is provided by Digital
Library of India – an undertaking of the Government of India. You can read and download the
Bengali Mahabharat credited to Sri Haridas Siddhanta Bagish Bhattacharya. You
can read the Bengali Mahabharata Online and there is also an option to download
but it works rarely. Please note that it is not in pdf format.
Link – This is the link to the first chapter of MahabharataEpic in Bengali. (You will need to download software to read the epic from the
website)
You can get the rest of the chapters by doing a search for Haridas
Sidhantvaagish in the author column here in this link.