Does not appear the sign of the currency

You need to add your custom formats to opendeals_module.module here:

/**
 * checks current currency and returns correct symbol
 */
function opendeals_module_checkCurrency($amount) {
  switch ($amount) {
    case 'USD':
      echo '$';
    break;
    case 'GBP':
      echo '£';
    break;
    case 'EUR':
      echo '€';
    break;
  }
}

You can change it in node--deal.tpl.php. The currency sign ("R" in your case) is rendered by
opendeals_module_checkCurrency($currency);

You have to change it in 3 places for price, original price and discount. Just move the currency function so that it comes after the format function. The first instance is price:

<?php
        opendeals_module_checkCurrency($currency); 
	    echo opendeals_module_formatMoney($price , 1);
?>

So you would change it to this:

<?php
        echo opendeals_module_formatMoney($price , 1);
        opendeals_module_checkCurrency($currency);
?>