If you are planning on launching in matter of couple of months, mono. If you are thinking 6 months and beyond, .net Core. Also, .net Core does not have feature

If you are planning on launching in matter of couple of months, mono. If you are thinking 6 months and beyond, .net Core. Also, .net Core does not have feature parity with .net4.6/mono, so you may want to know the gaps depending on the type of application being built.