Informal:
* کیا حال ہے؟ (Kya haal hai?) - This is the most common and direct translation, literally meaning "What is your condition?"
* کیا چل رہا ہے؟ (Kya chal raha hai?) - This means "What is going on?"
* کیا کر رہے ہو؟ (Kya kar rahe ho?) - This means "What are you doing?"
Formal:
* آپ کیسے ہیں؟ (Aap kaise hain?) - This is a more formal way of asking "How are you?"
The best translation will depend on the specific situation and your relationship with the person you are talking to.