I guess, it should be cummulative volume at a price level mentioned on the right axis.
I don't use this software but have seen the Cummulative Price on other softwares.
Hope these charts are helpful.. even i think in nifty its a pennant , rounding bottom,symm triangle or ascending triangle(depending upon where we draw the trendline) or a simple pivot break around 5000 as plenty of renowned TAs in traderji would call it...