South Africa captain Raynard van Tonder named the captain of the team that contains five India players.
Pakistan finish top in Group D means Afghanistan have to settle for fourth after third-place play-off is washed out in Queenstown.
The three-time champions will now face Australia - also three-time winners - in the final on Saturday.
Pakistan reclaim the top ranking in T20 internationals after their 2-1 series victory over New Zealand with 18 runs at Tauranga.
India beat Bangladesh by 131 runs and they will play Pakistan in semi-finals 2 of the U-19 World Cup 2018 on Tuesday, January 30.
Pakistan crushed New Zealand by 48 runs in the second T20 in Auckland on Thursday to notch their first victory of the tour over the Black Caps.