Below is the technical chart of Sensex, using Ichimoku Kinko Hyo indicator.
I've used weekly time frame on chart to get better picture of Sensex trading direction. It's currently trading near its major weekly support level viz. at kumo – 17,470. If it closes below this level on or before Friday, it sill surely going to kiss the levels of 16,900 levels, which is its next support level.