In short, you should choose Flutter if your budget is limited or you need to make a simple application quickly . Also, you can make a Flutter application if UI is core for your app. But if your funding is sufficient and you want to create a complicated app, go with React Native.
Read moreCan I learn Flutter if I know React?
If there is a person who already knows react then react-native will be the fastest way to build a mobile app. People are coming from java background for android development or probably . net or c# then flutter will much easier to deal with flutter framework . But something to remember flutter does uses dart.
Read more