If you want a single row, then something like below should work
SELECT SUM(rank) AS rank, SUM(total) AS total
FROM
(SELECT (COUNT(*) + 1) AS rank, 0 AS total FROM `rang_info`
WHERE `player_kills` > (SELECT `player_kills` FROM `rang_info` WHERE `player_name` = '%s')
UNION
SELECT 0 AS rank, COUNT(*) AS total FROM `rang_info`) AS temptable