I rooted my Gallaxy Tab GT-p6200 without taking a backup, changed it to cyanogenmod and rebooted it. It is working nicely but I can’t install the play store. I want my old OS or the play store. Please help me!
Gapps is normally not included with any custom ROM, such as CyanogenMod. Follow Griffin's suggestion in order to get the Google apps and services working.
Go to the CyanogenMod wiki and download Gapps! Then flash the zip with your custom recovery :)