Reading India VIX

(a) India VIX is 15. What one-day and 30-day one-standard-deviation Nifty moves does that imply at Nifty 25,000? (b) If subsequent 30-day realised volatility turns out to be 11%, what is the ex-post variance premium in variance units and in vol points? (c) Describe precisely how you would test, with India VIX and Nifty closes from NSE's daily index files (cached and read with toolkit.data.load(..., source="cache")), whether India VIX has on average exceeded subsequent realised volatility, avoiding look-ahead. What statistical problem do overlapping 30-day windows create, and how do you handle it?