Data suggests a Sideways Market for 18th. So would be looking to short incase I find a rejection with confirmation at any of the resistance levels shown. The opening of the trade would suggest the course of action. 18100 is a strong support and a break of that may give a good downward movement. Need to keep a watch on any addition in put or call writing during the course of the day. Accordingly one can make a strategy to play out this expiry.