What is the spot for settlement of Crude oil options on zerodha?

Like we look at RBI reference rate for currencies, where to find the same for different commodity options.

Settlement price on expiry day for crude oil option will be determined based on daily settlement price of the underlying futures contract

Merge commodity with main NSE . (single margin for all Equity/currency/F&O/Commodity.)
Keeping 2 funds seperately for equity & commodity is not practical for us &
hence trading in commodities stopped.