after iris is done blooming I got a green pod on the stem.
what is it , should i plant it?
It sounds like a seedpod has grown on your iris. It is possible to grow iris from seed but new plants won't bloom for 2 years. Division is the usual method for propagating iris at home. Some seeds may take more than a year to germinate so patience is vital. Since most iris are hybrids, seed grown plants won't look exactly like the parent plant - genetics at work. The following article explains the process: https://theamericanirissociety.blogspot.com/2017/02/growing-irises-from-seed.html