Harish,
use SAM
or
perl -e 'local($PSTAT,$PSTAT_STATIC,$mem_info,$PSTAT_STRUCT)=(239,2,"\0"x120,"LI4L");
syscall($PSTAT,$PSTAT_STATIC,$mem_info,length($mem_info),1,0);
print "RAM=".int((unpack($PSTAT_STRUCT,$mem_info))[4]*((unpack($PSTAT_STRUCT,$mem_info))[5])/(1024*1024))."\n";'
or
one of the numerous solutions in previous threads.