Bangladesh has a wide range of options. The more drastic measures are also much more risky. There are options ranging from the almost purely symbolic to extreme escalations, among them:
- Deliver a diplomatic note.
- Recall diplomatic staff.
- Make a case in the International Criminal Court that her actions do fall under the categories covered by that court.
- Increase tariffs on imports from India (e.g. electricity, fuel) or exports to India.
- Ban commercial air travel between India and Bangladesh.
- Ban any trade between India and Bangladesh.
- Declare a naval blockade and try to enforce it (they might be unlikely to win, but they might get lucky).
- Declare war and invade (same issues as above).
Just how far they are going to go will depend on their estimate of the likelihood of success and the cost to their own economy.