View attachment 629508
Blue will not even phase it! It might turn it. This would be the shot to take to try desperately to get it to stop charging without killing it (e.g. accidental elephant charge while hunting buffalo), but if this does not work and it is close and truly coming, you are about dead...
Red, above the eyes, and just above the upper end of the zygomatic arches, will maybe graze the top of the brain, especially with a shot angling up, but more probably go just over it. A 9.3, .375 or even .416 will probably not knock it down, but a .500, .470 or .458 Lott will most likely drop it but not kill it. You have about 5 to 10 seconds to run sideways and put another one in the top of its head or a couple behind its shoulder.
I would go a little lower than discussed so far because its head is held up; the shot is angling up; indeed "when in doubt aim low" (attributed to Richard Harland in modern days, but he could have just repeated it from older hands, and in any case advised by Charlton McCallum in his videos) and they do not mean 1" low but 4" low - it is an elephant after all; and the shot is still in line with the zygomatic arches.
PS: red would work if it is coming for you from below, e.g. it is in a shallow river bottom and you are on the bank 4 to 6 ft higher than it.