Will I need to break concrete around the toilet drain pipe in the concrete in order to get the flange on or do they go on the inside of drain pipe?

Will I need to break concrete around the toilet drain pipe in the concrete in order to get the flange on or do they go on the inside of drain pipe?
No, they make a inside flange. When we rough for a toilet in my area we install a styrafome closet wrapper. Sometimes the cement guys overpour this. Tap around the stubup with a hammer to see. If there is a overpour and a closet wrapper you can dig it out with a screwdriver. Regards, Tom