dose anyone know how to become a অনুরাগী of someone?

It's really simple:
1. Go to their পরিলেখ দ্বারা clicking on their name পরবর্তি to any of their content অথবা comments.
2. Select the "Add to Friend List" button which is on the bottom left of the first grey box.
3. This button will then change to say "You're a fan!"

If clicking on their name leads আপনি to the ফ্যানপপ main page instead of their profile, this means that their account has been closed. It isn't possible to অনুরাগী someone who's account is closed.