There is a unique maximum quantity limit defined by the exchange (MCX) for each contract. Your order quantity has to be less than the maximum quantity specified by the exchange, otherwise your order will get rejected.
What happens to long positions in commodity future contract expiry on the first day of the tender period?
What happens to short positions in Expiring future contracts during the tender period?
How can I trade in commodity options in Kotak Neo?
How do I activate Commodity Trading in the Kotak Neo app?