I have found the tracking of Nifty on Intra-day plane by using GANN's Tool is very reliable one.
I am giving here a very cost effective tool simply involving Rs.2=50 only. I had purchased one Transparency sheet (Plastic sheet - 7" x 9") from local Stationery shop. I have drawn Gann's Geometrical Angles : 75-Degree, 63.5, 60, 45, 37,33.5, 22.5 and 18.25-Degree angles on the sheet with the help of Degree-Scale (may be available in your home geometric box) with the marker pen (obtained from local stationery shop). Now you use this drawn-up-sheet on the and place it on the screen of the computer on the face of the Nifty Chart. Try to identify - when the Index is standing on 63.5-Degree but prepares to get down - it may hit 37 / 30-degree so you can buy one PUT call. Conversely, currently the Index is on 22.5-Degree it may go up to hit 45-degree, go for CALL option. One thing to be kept in your mind, I have seen, Gann's - 62.5-Degrr, 45, 22.5 are very important angles while trading on a Inter-day plane.