To change the Read more… text for the buttons of out of stock ticket types, you can add the following as PHP snippet using Code Snippets plugin:
​

add_filter( ‘woocommerce_product_add_to_cart_text’, ‘tc_change_read_more’ );

function tc_change_read_more( $text ) {
global $product;
if ( $product && ! $product->is_in_stock() ) {
return ‘Out of stock’;
}
return $text;
}

Now, although the text will change, this will still be a hyperlink that, by default, will lead the customer to the product page. So, to prevent them from accessing the product page, you can navigate to Tickera Settings -> General tab -> WooCommerce area and set the option Redirect product single post to an event to Yes. As a result, if a customer clicks this Out of stock, it will lead them to the page of the event which this ticket type belongs to instead of WooCommerce’s product page.