In-game menus and mission dialogues are often translated into Bengali.
Since this is not an official app, you won't find the "Bangla" version directly on the Google Play Store . Instead, users often turn to:
Usually, you will download a .zip or .rar file containing both the APK and the OBB data.
Look for a folder named com.rockstargames.gtavc . Move this folder to your internal storage: Android > obb .