What It Means
COMEX, NYMEX, and LME are the major international exchanges whose prices Indian commodity contracts track. COMEX (part of CME Group) is the global benchmark for gold and silver futures, NYMEX (also part of CME Group) sets crude oil and natural gas benchmarks, and the London Metal Exchange (LME) is the reference market for base metals like copper, zinc, and aluminium.
How It Works
MCX contract prices move with two things at once: the dollar price on the relevant international exchange, and the USDINR exchange rate, since global commodities are priced in dollars and MCX prices in rupees. A day where international gold is flat in dollar terms can still see MCX Gold move if the rupee weakens or strengthens against the dollar, and the reverse is just as true.
Example
If COMEX gold is unchanged at $2,650 an ounce but the rupee weakens from 87.00 to 87.50 against the dollar, MCX Gold rises in rupee terms even though the dollar price didn't move, purely from the currency effect.