1) Option chain data: Highest total OI and highest fresh PUT writing is at 27000 strike which is too far low. Near ATM, data is not conclusive enough so one cannot say with conviction that this strike can act as good support. On CALL side, total highest OI and highest fresh call writing is at 28000 but near ATM data is equally inconclusive as for PUT side.
2) Chart : On , BNF made higher high and higher low as compared to previous candle. BNF has 20 at 27645 which might act as resistance. If you see top 5 weightage stocks of BNF ( HDFC Bank , ICICI Bank, Axis Bank, Kotak Bank & SBI ) which contribute more than 80% towards BNF, you will realize that these are also approaching or near their 20 levels. Combining bad effect of Auto sales data on Nifty with charts we see there is a selling area as shown on chart. So trade with strict SL as shown.
All the best . Happy trading