Probation Dilemma: Can My Manager Enforce a Notice Period When My Contract Says Otherwise?

Hi, I am on a probation period, and in my appointment letter, it's written that during this period there is no notice period. However, my manager is insisting that I serve 15-30 days. I have also received a job offer which requires me to join next week due to a new project. What should I do? Please help ASAP.

Yes, as mentioned in the previous comment, the organization or manager cannot hold you back. This is the height of incompetence on the part of the manager. Also, let HR know about the incompetence of the manager so that you can ensure future employees are not made to suffer again. HR needs to show the manager the door.