Does anyone know how can i get my routerOS kernel Version.
Because I need to know if it supports an optical fiber card. 
/system package print
It should so you the version of all installed packages on the MT.
If it’s not on the supported hardware list then it isn’t supported.
http://www.mikrotik.com/docs/ros/2.8/guide/driverlist.main
Regards
Andrew
well that’s to know package version, but i need to know kernel’s version on which mikrotik is running. Beacuse a wanna buy an optical fiber card, and it works with kernel 2.2.5 or later
but this is a proprietary Network Operating System, not an open sourced Linux OS. Check the MT supported hardware as that is what is supported anything else you’re taking a gamble on.
Good luck.