Formal:
* আপনি কি ব্যস্ত আছেন? (Aapni ki byasto aachen?) - This is the most polite and formal way to ask.
* আপনার কি সময় আছে? (Aapnar ki somoy ache?) - This means "Do you have time?" and is a more indirect way to ask if someone is busy.
Informal:
* তুমি কি ব্যস্ত? (Tumi ki byasto?) - This is the informal way to ask someone if they are busy.
* তোমার কি সময় আছে? (Tomar ki somoy ache?) - This means "Do you have time?" and is the informal version of the previous sentence.
You can also use different verbs depending on what the person is doing:
* আপনি কি কাজ করছেন? (Aapni ki kaj korchen?) - "Are you working?"
* আপনি কি পড়ছেন? (Aapni ki podhchen?) - "Are you reading?"
* আপনি কি খাচ্ছেন? (Aapni ki khachhen?) - "Are you eating?"
Remember to adjust the level of formality based on your relationship with the person you are speaking to.