I have to cut out old tee made of cast iron must be 2 inch to replace wit either rubber tee or abs

We need more details. How much cast iron's above the tee you wish tom replace? What does the branch of the tee service? Why are you replacing this tee? I'd stay with a plastic fitting and not rubber. Back to you, Tom

Tom is absolutely correct... Plastic fitting will collapse under weight of cast iron. Also, make sure you support the existing pipe before you cut it. Otherwise, it may drop down on your hands.