usually I've come across hedge fund strategies which try to predict and anticipate which stocks are going to be added and removed and then take long/shorts in them.
however it may be a bit too late to do that here i think?
i don't think the stake sale has much of an effect here, it's more relevant for other Tata group companies than IT companies.. It looks like the stake sale was a step in the direction of the company not having to do the IPO. It will probably do more such actions