It is unclear what you mean by „assessing the security feature“ or „find the security implementation details“.
readelf -r displays the information in an ELF binary’s
.rela.plt and (if present)
Displays the contents of the file’s relocation section, if it has one.
Print the relocation entries of the file. If used with -d or -D, the relocations are printed interspersed with the disassembly.
Print the dynamic relocation entries of the file. This is only meaningful for dynamic objects, such as certain types of shared libraries. As for -r, if used with -d or -D, the relocations are printed interspersed with the disassembly.
The information in these sections pertains to symbol resolution:
Relocation is the process of connecting symbolic references with symbolic definitions. For example, when a program calls a function, the associated call instruction must transfer control to the proper destination address at execution. Relocatable files must have information that describes how to modify their section contents. This information allows executable and shared object files to hold the right information for a process’s program image. Relocation entries are these data.
Unfortunately, you don’t share any information about the binary being analyzed, but there is a good chance that most of the memory addresses (offsets) of symbolic definitions reside in the Global Offset Table.
What this has to do with „security features“ is not clear to me.