Hi,
I will get my wife's ITIN in probably next 4-6 weeks. Can I efile in websites like taxactonline for state etax with that itin? Or should I do only manual file as I am filing with "married" status for the first time?

Also please do let me know that How can I know that IRS has accepted my federal tax submission. I have done manual filing this year as I have to apply ITIN for my wife

Is your wife eligible for ssn at some point?

No

You should be able to efile state return with ITIN.

Thanks. Can you please answer my next question as well?
"Also please do let me know that How can I know that IRS has accepted my federal tax submission. I have done manual filing this year as I have to apply ITIN for my wife"

If you get BOTH the ITIN and the refund, you know the IRS has processed your return and accepted it as filed.