Highest individual score on an IPL debut

In the first match of the IPL history, when a total of 22 players made IPL debut, New Zealand cricketer Brendon McCullum scored 158 not out off 73 balls during his service for the Kolkata Knight Riders (KKR). In that historic match, KKR faced the hosts Royal Challengers Bangalore (RCB) at Bengaluru on 18th April 2008. McCullum’s 158 not out (10 fours and 13 sixes) helped the KKR to manage the first innings total of 222/3 (20 overs). In reply, RCB were bundled out for just 82 runs (15.1 overs) as KKR won that match by 140 runs.
It is very hard for an IPL debutant to score 150+ runs as only two batsmen have managed to score 150+ runs in an IPL inning. So, Brendon McCullum is likely to secure this record for more years.