Is it possible to create instance of BP type in c++ Ctor

You have two main problems here, both with your call to NewObject.

First, the first parameter to NewObject isn’t the class type but the outer (sort of the owning object). In your case you can probably use this as the first parameter.
Second, you don’t need to call anything with your TSubclassOf member when passing it to NewObject. You can pass it directly in as the second parameter to NewObject.