The issue can be resolved with one of the following approach:
Navigate to Application Skin--> Radio Buttons--> Standard Control--> Uncheck "Use browsers default radio buttons"
Navigate to Application Skin--> Radio Buttons--> override standard control and check the runtime.
Let me know if it helps.
I am seeing another type of issue in Radio Button. This Radio Button is sourced with a Boolean Property and has been used in a Table inside a section. On runtime the radio button is not visible and on selecting it appears like a Big Black Box.