I had a cast on my hand and went to remove it at the hospital today , how long before i regain full flexibility and before the swelling goes away?

Everyone's different: Flexibility will come back gradually as you work on improving your motion. The more consistent you re, the faster it will return. Assuming your fracture healed and your anatomy has been restored, you should exect to regain your full motion eventually.

Depends: Whithout knowing what the injury was, it is hard to say what time will be necessary for full recovery and if that is even possible.