It might be
echo $users->pack_info($uinfo['package']['max_attack_time']);
instead of
echo $users->pack_info($uinfo; ['package'] )['max_attack_time']
edit
assuming you are trying to do function array dereferencing (which requires php>=5.4) it might be
echo $users->pack_info($uinfo['package'])['max_attack_time'];
solved Parse error: syntax error, unexpected ‘[‘, expecting ‘,’ or ‘;’ on line 30