When can I place after market order (commodity) to be executed on Monday? Should I punch it on Sunday or Friday itself?

Sunday is ok. So you can place AMOs at Saturday or Sunday, anytime is ok.

You can place after market orders from Saturday to Monday morning before market opens. I.e till 9:59 am and ever day you can place amo orders post market close .

Is it not the AMO orders for commodity MCX can be placed during Trading Hours.
I think it is possible to place AMO order after Saturday morning 10 am, which will be executed only on Monday morning 10 am.
If placed before Saturday 10 am, it will be executed on saturday itself.
But I think in equities, NSE and BSE, AMO orders cannot be placed during trading hours and can be placed only after 6:30 pm. In case commodity, I think it is possible to place during trading hours also. Please correct me if I am wrong.
Why I have suggested after market close on saturday is that, during saturday trading values would change and the trader can get an idea what limit value to be placed for AMO which can be executed on Monday morning.

There is no mcx market on Saturday and yes you can place after market orders in market hours as well . It will be executed on next working day only.

Thanks for clarifying that.
Which market will be open on Saturday, so that trading can be done in Saturday (i.e. office holiday).
Can you suggest?

No market is open on Saturday. All exchanges are closed, in case if you see any it will be a mock trading or just a server up-gradation testing will take place on some Saturdays, so we see some movement in the prices.