Bank nifty has reversed from 1.618FE of wave 1. IF it takes support at the 38% or 50% fib levels (and the trendline), then it could result in a sharp up move to new highs. This should pull Nifty too; just that the wave structure is clearer here.
(Support at the 23% fib level for the up move after that is possible too but then an initial entry would be difficult...
There is a possibility of sudden 700 points sell off in nifty, i can see some short patterns in nifty and bank nifty charts, there is also heavy PUT buying going on, VIX is ticking up, global markets are also suggesting a sell off, and INR is also not getting strong..
Bank Nifty seems to be forming a Flat pattern, following it should give the final impulse up. The structure's completion can be watched in conjuction with the Nifty chart (linked) to complete it's correction.