Yes, you can use the ScrollToCaret()
method:
// bind this method to its TextChanged event handler:
// richTextBox.TextChanged += richTextBox_TextChanged;
private void richTextBox_TextChanged(object sender, EventArgs e) {
// set the current caret position to the end
richTextBox.SelectionStart = richTextBox.Text.Length;
// scroll it automatically
richTextBox.ScrollToCaret();
}