Today after the gap-up opening, both indices traded within a narrow range and ended the session in green.
Tomorrow in Nifty, the 17880-840 zone will play an important role. A sustainable move below that zone can take the index towards 17750/690/600 levels. And on the higher side, the 17980-18010 area will act as a strong resistance.
And in Bank Nifty, the 40690-40750 zone is crucial. If Bank Index holds above that zone, then it can move towards 40900/41200/41600 levels. And on the lower side, the 40200-100 zone is the support.

Nifty Intraday Gann levels
Nifty bulls need to break & sustain above 17980 to move towards 18020/18070/18130/18200.
On the lower side, the Gann support level is 17880; below that Index can move towards 17840/17790/17730/17660.

Bank Nifty Intraday Gann levels
Bank Nifty bulls need to break & sustain above 40750 to move towards 40900/41100/41350.
On the lower side, the Gann support level is 40400; below that Bank Nifty Index can move towards 40250/40050/39800.
Note: The above levels are for educational purposes. Not Buy/Sell advice.