In case Nifty opens above 17600 levels and if you get a chance to test R1 or Bullish Breakout zone of 17582 at opening and confirms a support, then we can expect upper resistance targets 17670 & above.
In case 17680 taken out and sustains then we can expect 17820.
Any resistance from Breakout T1 & T2 at opening we can look for possible shorting opportunity and expect Nifty to test R1 & may be PDH.