Red lines are resistance area and Green lines are support area.
On Monday, if BankNifty breaks the green trendline, then it may fall further. So, in case it breaks Green trendline then wait for it to retest the Green trendline to enter into a short trade in future or short BankNifty ATM Call option.
On the other hand, if it breaks red trendline then wait for it to retest the red trendline, then go long in future or short ATM PUT option.