Ya you can backtest it last 1 year. you ll know it.
VIX was highest before election results and nifty was going towards moon one way direction "UP". The theory that vix goes down when index goes up fails there itself. I also wish to add when index goes up and vix goes up does that mean markets going down no it never went down after results for sometime..
The rest you can back test it and come up with your doubts.