In the past, the authors of the randomForestSRC package have published a couple of articles on the subject that you may find useful for developing predicted survival curves.
For example, in this article, the authors provide some R code used to "predict" survival curves for a new set of data that they created on 3 made-up individuals to assess the "accuracy" of predicted survival curves.
On a side note, I have been unsuccessful in finding much literature on the use of random forests for survival curve prediction; hence, I am wary about applying such modeling to real-world applications - especially, since it is a paradigm shift from inferential to predictive application.