Is an Offer Letter Legally Binding if My Start Date Keeps Getting Delayed?

I would like to know if an employer is delaying the joining and not specifying the date when the company can be joined, is the offer letter a legal contract that can be used for legal proceedings?

Note: The offer letter has been accepted, and the candidate has been released from the current organization. The company is citing the reason for the delayed joining as a business situation.

A job offer letter cannot be treated as a legal document. It is only a Letter of Intent (LoI), offering a position/job to a prospective candidate. However, an appointment letter from a company shall necessarily be considered as a legal document.

Have you received an Offer of Appointment from the company?

Not yet, as I believe it is received after candidates get onboard. But in this case, joining itself is being delayed.