chapters 16 up to and including chapter 23 will be sufficient
However,I see that "Using Timer Objectives" and "Implementing Security" objectives for certification are not covered in the chapters up-to 16 and including chapter 23.
Please advise if your notes and OCP JavaEE 6 EJB Developer Study Notes by Ivan are sufficient for the same
I am not sure to what objectives you are referring but the chapters Timer Service (chapter 16) and Security Management (chapter 17) cover everything for the exam about those topics. Actually I can say that I didn't get any questions outside the specifications at all (well you should also be able to read and understand a given deployment descriptor)
This chapter describes the interoperability support for accessing an enterprise bean through the EJB 2.1 remote client view from clients distributed over a network, and the distributed interoperability requirements for invocations on enterprise beans from remote clients that are Java Platform, Enterprise Edition (Java EE) components. Distributed Interoperability is not defined for the EJB 3.x remote client view.