I also marked S/R levels on chart yesterday and this is how one can trade those levels on Nifty Future. Here are the Nifty spot and future charts.
Here this is how one should try to read the prices. "On Big Picture, weakness in bulls. Opens full gap down - indicating weakness. Takes support at NF BRN but fails to break above morning high indicating again indicating weakness. After trading in a narrow range breaks down below NF BRN and trades below BRN, which confirms the weakness. After that it breaks the support level in Spot and trades below the support." So here is the opportunity and it is time to take the trade as BPB.
Always try to read the price action and be in sync with whatever you are able to read from the prices. You will most often get at least one good setup to trade during the day.