Nifty- Its time to look at FIB Retracement levels

Nifty breached the critical resistance level of 18276 with a strong green bullish candle today. With the next level close to all time high levels, it's time to use Fibonacci retracement tool to find the next possible highs for Nifty. So the next resistance levels (pivots) are 18605,18728 and 20105. The 20k level looks a bit far fetched as of now however the vix calculations indicate the target is very much in sight this year. In fact it points to a possible upside of 21377 in next 12 months. How soon it will come is anyone's guess. The fib retracement levels are also similar & marked on the chart. PCR is 1.1 --slightly positive bias of option writers, and CPR is 22points wide indicating a trending market tomorrow.
FII and DII both sold today for 971cr which is one worry at present....but the positive point is that markets posted a gain despite this. So when they turn net buyers, the market could actually shoot higher...what do you think is the possible upside in the next few sessions?