I am using two different version on ubuntu one is 14.04 and other is 15.10. I want to read 14.04 systems sar files from ubuntu 15.10 system. I have transferred the sar files but can't read it.
Different version of sar files are not necessarily compatible and I think the file format changed between those versions you have. You can either downgrade sar on your system or try to install the exact version you have on the older system. If you just need the information you can dump out it to text version on the older box .
See one example from SO: