Plz suggest me a suitable code so that when i click on the 32bits value radio button it will call the subroutine 32bits_value()
You need to make a distinction here. While clicking on the radio button is a client-side event, the actual function lies on the server.
In order for a client-side event to trigger a server action, you need to send a request to the server (aka Postback request). There are several ways of doing that, from reloading the whole page, to a specific AJAX call (which won't load the whole page).