a politically correct answer.
northernmost part (disputed, administered) - near indira col, siachen glacier - 35.674520°n 76.845245°e
northernmost part (disputed, claimed) - dafdar near beyik pass - 37°24′00″n 75°24′00″e
northernmost part (undisputed) - near dharwas, chambal district - 33.24902°n 76.82704°e
southernmost part (mainland) - cape comorin - 8.06890°n 77.55230°e
southernmost part - indira point in the nicobar islands - 6.74678°n 93.84260°e
distance between:
1 & 4 - 3070 km
1 & 5 - 3654 km
2 & 4 - 3269 km
2 & 5 - 3885 km
3 & 4 - 2801 km
3 & 5 - 3430 km
explanation: