If you have not given your acceptance for notice period of 45 days, then notice period shall be 30 days.
The notice period can not be increased arbitrarily, by any number of days e.g. 30 days as posted by you.
Kindly read your appointment letter and email of director informing increase in notice period and email communicating relieving date, carefully, and relate.
Company might have written:
-in your appointment letter that all terms and conditions communicated to employee from time to time shall be acceptable to employee.
-in email increasing notice period that you may confirm within....days, or it shall be construed that the change is acceptable to you.
- in email informing relieving date that due to various ongoing projects assignment son hand your relieving date is......
If deemed fit you can seek clarification in writing from company; therefore you may send a gentle communication to the director, in writing under acknowledgment.
You may use your rapport and finish the assignments in hand within 30 days of your notice of resignation, submit company property and obtain clearance and NDC from your concerned authority. If possible you may help them to find your replacement.
Be gentle, amiable, persuasive and use your negotiating skills and obtain your F&F, work experience certificate, form 16,PF accumulation reports, PF transfer/withdrawal forms, NOC/NDC etc...
It is understood from various posts from your sector IT, sometimes situations crop up and settlement of accounts of employee becomes tedious.
Be smart.