<?php

$cobenations = array(
  array('g', '9', '6', 'Г', 'Γ', 'r'),
  array('o', '0', 'о', 'ο', '()'),
  array('a', '4', 'а', 'α', '@'),
  array('t', '7', '+', 'т', 'm', 'τ'),
  array('s', '5', 'с', 'σ', 'c', '$'),
  array('e', '3', 'е', 'ε')
);


function addVorecia($cobenations, $level, $part = '') {
  if($level > 5) {
    echo $part . PHP_EOL;
  } else {
    foreach ($cobenations[$level] as $cobenation) {  
      addVorecia($cobenations, $level + 1, $part . $cobenation);
    }
  }
}

addVorecia($cobenations, 0, '');