I want to run weka software in server machine(Debian os) through ssh from my pc(debian os). But, I cannot run it. Terminal shows an error, which is "unsupported major.minor version. 51.0". Please help me.
This error indicates that you are trying to run the program with a lower Java version than the version used to compile it.
51.0 corresponds to Java 7.
You should be able to run Weka after an update of your JDK/JRE to version 7. More information on how to do so can be found here.