Dear Satendra Singh,
If you submitted the resignation on 18th December 2022 with a 30-day notice period, then how your last working day will be 6th Jan 2023? Excluding the date of resignation, it has to be 17th Jan 2023.
Your resignation has to be routed through your manager. Before submission of resignation, did you speak with him and explain that you wish to separate from the organisation? If yes, what did he say? Did you request him to forward the resignation to me HR department?
If your emails are not responded to, then did you try to speak with the manager on phone? If yes, then what did he say?
If the resignation is not processed, then you could have done immediate follow up in the last month itself.
Thanks,
Dinesh Divekar