Informal:
* মজা করছি (moza karchhi): This literally translates to "I'm joking" and is the most common informal way to say it.
* হাসি (hasi): This means "laughter" and can be used to indicate you're joking, especially if you're being lighthearted.
* ঠাট্টা (thattā): This means "jest" and can be used to indicate that you're teasing someone.
Formal:
* মজা করে বলছি (moza kore bolchhi): This is a more formal way of saying "I'm joking" and is often used in written language or in formal situations.
* ঠাট্টা করছি (thattā karchhi): This is a more formal way of saying "I'm joking" and implies that you are being humorous.
Other phrases:
* আমি মজা করছিলাম (ami moza karchilam): "I was joking"
* তুমি কি মজা করছো? (tumi ki moza karchho?) "Are you joking?"
* এটা ঠাট্টা (eta thatta): "This is a joke"
The best way to choose the right phrase will depend on the specific situation and your relationship with the person you're talking to.