If you’re an Indian fan, you’ll want to keep your calculator handy. The only way India can qualify for the semifinals is if Pakistan beat Australia and India beat the West Indies on Wednesday.
Any other result in either game will rule India out. Pakistan are already through with four points from two games. Australia have three and India one.
A washout or tie in the Pakistan-Australia match will kick India out (a tie will have Australia move to 4 points, which India cannot reach even if they get two points for beating the West Indies).
In case of India and Pakistan both winning, India and Australia will be tied on three points apiece, brining the net run rate into play. As of now, with a NRR of +1.00, Australia are some way ahead of India, who have an NRR of -1.08.
This means that Australia have scored 50 runs more than they have conceded (while beating West Indies), while India have conceded 54 runs more than they have scored (while losing to Pakistan). The rained out match does not count.
Ideally, India will want Pakistan to beat Australia by at least 104 runs (50+54), which will mean that India just need to beat the West Indies to go through.
On the other hand, if Australia lose by 50 runs, and India win by over 54, India goes through.
If India bat second though, things get more complicated. They would have to knock off the target with plenty of overs to spare. In short, India need Australia to lose badly, and then hammer the West Indies.