Dear Rahul,
Sec 321 Crpc is for " widraw from case " by the prosecution. Means PP will file the application of 321 crpc that accused should be discharged from this case, PP can file this application any time before judgement there is no need for the accused to be present on that day.
If court is going to discharge them there is no need accused to be present.
If in any case, court order the accused to present then you can file exemption.for the same.
