The Bank Nifty index witnessed a volatile trading session, mainly declining due to a fall in HDFC Bank. The index is currently stuck in a range with resistance visible at 53000-53200, where aggressive call writing is observed, and support at the 52300-52100 zone. The index needs to break decisively on either side for trending moves. However, within the range, the view remains bullish, and declines should be utilized to buy the index.