If you cannot find a legitimate free PDF, do not resort to piracy. Check your local college library or buy a used physical copy of the Bangla translation—it often costs less than a cup of tea. However, for students on a budget, the 19th-century public domain translations (if you can read older Bangla script) are a godsend.
These are harder to find but offer the full depth of Dumas' social commentary and intricate subplots. The Count Of Monte Cristo Bengali Pdf
Which would you like?