NIFTY rejected 4 times at 21500 levels, need to watch the trendline. Possible chances for made high today and then it rejects strongly.
Also, today is an important day as per astrology. Let's watch the day.
Look at the DEC 13th, when it rejects from 17643 levels possible closing is 17374.
Now look at the Friday closing it's almost same. Next day DEC 14th what happen opened gap down so possible chances of gap down and Market can raise up.
For best entry and exit look at the DEC 14th chart.
Hope this gives you a little bit of idea how to analyze the chart.