There are four variants: If you are addressing a male: 1, Aap kiya kar rahe hen (formal) 2. Tum kiya kar rahe ho (informal) Addressing a female 1. Aap kiya kar rahi hen (formal) 2. Tum kiya kar rahi ho (informal) Here "hen" is pronounced like "can" but n is nasal.

aap kya kar rahy ho?

Aap kia kar rayhy ho

Aap kia kar rahy hain?

Answer of this question is that: Ap kya kar rahe hy?