Can I join any of the online universities? If so, will they provide the subject details and notes to us through mail? How will we pay the fees?
- answers

The simple answer it yes, but there is a catch. You have to be accepted. Now, for that you must meet the requirements of the university or college. All of which, are unique to the school and the program you are applying to.
What I am going to suggest you do is take a look at these list of articles,
Each of these list are an excellent source of information on online education.
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