Scenario 1 :- If Bank Nifty opens flat and trade flattish at the level 42870, go for put Option or Future selling with Strict Stop Loss of 42885 for target of 42350.
Scenario 2 :- If Bank Nifty breaks high of today's level than, go for call Option Buying or Future buying with Strict Stop Loss of 42855 for target of 43300. But it can be very risky trade, so take minimum positions.