Depends what you are expecting. Korma is derived from the Hindi word meaning 'braised' so the sauce you use to braise whatever it is you are cooking could be anything.
Unfortunately, westernized Indian restaurants have this 'code' whereby korma means mild and creamy with nuts (usually almonds or cashews). If this is what you are looking for then you it is easy to get commercially from the internet.
It is relatively easy to make and I have a Chicken Korma recipe on my sitewww.my-indian-food.com