there are some issues with handling map and list via remote java api in 6.1. You can search this forum to look at some workarounds. One of these are to use addExtraClasses via client api.
thanks. I was able to work with array of custom types. It requires explicit xml authoring unlike for eg: JPA where @xmlRootElement would do.
I've not tried it with Map or List
For now, this solution works for me.