McCullum scored a historic 302 on the opening session of day while Jimmy Neesham smashed a century on debut as the hosts declared their second innings at 680 for eight in 210 overs with an overall lead of 434 runs. (Agencies)
McCullum struck Zaheer Khan for a four in front of third man to reach the landmark in the 200th over of the Black Caps's second innings at a packed Basin Reserve.
At lunch, India were at 10 for no loss off four overs, chasing an improbable 435 runs for a win. Shikhar Dhawan (2 not out) and Murali Vijay (7 not out) were at the crease.
McCullum's 302 runs overtook Martin Crowe's 299 scored against Sri Lanka, also at the same ground, in 1991 to become highest individual Test scorer for New Zealand.
It was also the third-highest innings by a number five batsman in Test cricket after Michael Clarke's 329 not out against India in 2012 and Sir Don Bradman's 304 against England in 1934.
McCullum's effort is also the second-highest individual score in the second innings after Hanif Mohammad's 337 against West Indies in 1958. Overall he is the 24th Test batsman to hit a triple-hundred, while this is the 28th instance of a triple-hundred being scored.
McCullum started the final day of on 281 not out, needing another 19 runs to get to that magical landmark.
At the other end was debutant Neesham (67 not out) as New Zealand started from the overnight score of 571 for six under overcast skies.
It didn't matter much as Neesham cut loose almost immediately, while McCullum was more subdued as he took his time.
McCullum scored a historic 302 on the opening session of day while Jimmy Neesham smashed a century on debut as the hosts declared their second innings at 680 for eight in 210 overs with an overall lead of 434 runs.