like in nse we get to know pre open market i cant find the same for mcx and is there any way to know to exactly know where will a certain commodity like gold,silver,crude open
also how do people here place amo order how do they know at what price order should be placed
No, also pre open will be for only spot but not for futures, what trades on mcx are future contracts.
Any price user wish to can be placed provided it falls within circuit limits. All commodities are globally traded, so based on that one can guess the opening price within small error.