We know that VIX most of the time reflects the investor/traders sentiment. When VIX is higher it means lot of fear in the market and lower VIX indicates lack of fear in the market. The problem is the sentiment can be measured only Indices like Nifty as the Volatility Index VIX is derived from implied volatility of Options. In such a case VIX FIX comes handy to replicate the VIX behaviour in other instruments like Commodities, Forex, Stocks.