بسم الله الرحمن الرحيم
You are a Hanafi so you should lead witr salah according to Hanafi School of Fiqh. According to Hanafi Fiqh witr salah is three rakah with one salam. However, those who pray behind you their salah will be valid without any karahat though they follow Shafai School, you should not worry.
Allah knows Best!
Darul Uloom Deoband
This answer was collected from the official ifta website of Darul Uloom Deoband in India.