What was Ian role in The Lord of the Rings?

You're likely thinking of Frodo Baggins from The Lord of the Rings. Ian isn't a character in the story, but the name of the author, J.R.R. Tolkien.

Perhaps you're thinking of Ian McKellen who played the role of Gandalf in the Lord of the Rings film adaptations.

Let me know if you have any other questions about the story or the movies!