Add new OS support and functionality to the Shell script

I have already created a script - its a plain vanila script. Need Professional help to update new functions and OS Support Like {rhel6,rhel7,Centos6,Centos7,SLES 11,SLES 12,OEL6,OEL7 & Ubuntu) i would like to include Functions to Each OS. So its easy to manage and work in future. there is also a last function which will have CSV file generation. which needs to be tweaked as per the OS version and OS Type. GetOps function needs to be added so its easy to run across the servers without manual intervention.