You need to look at the next month rate of crude oil trading on CME, and multiply by the exchange USDINR rate to get current month theoretical MCX crude contract value.
You can check the rate of crude on CME on this link.
So for example, to find the price of July crude on MCX,
August crude is currently at $45.70, USDINR on NSE at 67.2825
So technically July crude oil on MCX should be 45.7 * 67.2825 = Rs 3075