Example of how to remove a ticket from the ticket selector is the current use already has a registration on that ticket linked to their contact.

example.php

<?php

add_filter( 'FHEE__ticket_selector_chart_template__do_ticket_entire_row', 'tw_remove_ticket_with_previous_registration', 10, 2 );
function tw_remove_ticket_with_previous_registration( $ticket_row_html, EE_Ticket $ticket ) {
    // pull the ticket capability set on the ticket.
    //$cap_required = $ticket->get_extra_meta('ee_ticket_cap_required', true);
    //if (empty($cap_required)) {
        // no cap required so user has access by default
        //return $ticket_row_html;
    //}

    // Check the user is logged in
    if ( is_user_logged_in() ) {
        $user = wp_get_current_user();
        if ( ! $user instanceof WP_User ) {
            return $ticket_row_html;
        }
        // is there an attached EE_Attendee?
        $att_id = get_user_option( 'EE_Attendee_ID', $user->ID );
        if ( empty( $att_id ) ) {
            return  $ticket_row_html; //bail, no attached attendee_id.
        }
        // grab contact
        $contact = EEM_Attendee::instance()->get_one_by_ID( $att_id );
        // if no contact then bail
        if ( ! $contact instanceof EE_Attendee ) {
            return $ticket_row_html;
        }
        // does the user have a registration for this ticket?
        $registration = $contact->get_first_related(
            'Registration',
            array(
                array(
                    //'EVT_ID' => $post->ID,
                    'REG_deleted' => false,
                    'TKT_ID' => $ticket->ID()
                ), 
                'order_by' => array('REG_date' => 'DESC')
                )
        );

        // if they already have a registration on this ticket, remove the ticket from the ticket selector.
        if( $registration instanceof EE_Registration ) {
            return '';
        }
    }

    return $ticket_row_html;
}