Hiya,
I Have A Brand New Hotpoint Washing Machine (WMUD 962P) And There's A Key Sign And It Keeps On Saying F06 On the Screen And The Door Won't Open, So What Shall I Do?

If it is a brand new washer, consult the owners manual for unlocking details. If you can't do it, call the service dept. and they can walk you through the process. Try unplugging the washer for a couple minutes and try again.