So what we do is buy long options. Remember is directly related to option price. Higher the vol, higher the option price (both call and put). But again we are not sure of the direction, so we should buy both a call and put. Now which strike to choose? It has to be out of money for feb expiry. This is a classic long strangle.
Buy any strike with equal distance from NIFTY at your point of trading. So e.g., if NIFTY is at 11000 then do +/-200 points strike on both direction (delta neutral to an extent). So 11200 call and 10800 put. You can choose your own range based on time of trading but important to remember that you choose out of money strike.
Since this is a pure vol trade ( vega capture) you should not hold it for more than 7-8days (max 12th Feb). This is because as the expiry is near ( vega ) losses its significance. Close the trade when vol spikes and you see one of the side of trade is significantly higher than other giving an decent overall profit.
All the best and hope the trade proves to be rewarding for you.
I see the weakness is still on cards but its losing the momentum by each day. I suggest covering your long puts and keep holding on long call for now. On long call, you should look to square it off over next 10days wherein I expect couple of huge upside nifty moves during this period.