There're a few things to consider in order to IDENTIFY an up-breakout here. Such as Volume and Price change, Previous Resistance, News, etc.
I have points out few from the charts. Previous Resistance is at 27777. Trading in small range is also important for a breakout.
In the TradingView.com, is not showing Volume so that i can give some steps to identify flow of demand and supply. suppose to increase price with huge volume can be up break out. volume increasing without raising price can be profit booking. Well, as per my prediction there lot of chance to stay in small range for BankNifty if stable volume.
Wait for changing huge volume and price. is good for seller.
i think analysing hdfc bank can help to figure out more accurate about bank nifty because of its weightage , hdfc bank is elephant of nifty 50 and bank nifty which can change direction of entire bnf