Should I let HR know if I am attending an interview twice within 6 months before joining, as per company policy it is not allowed?

Let’s say you applied for a job 4 months ago - then applied again today. In both instances, you were not an employee of the company. You were a candidate. By definition, you are not subject to the policies of a company if you are not their employee.

You violated a company policy and you are asking us if you should tell HR? Seriously?

My guess is that it is not a company policy, but a rule they put in place to discourage candidates from applying over and over in a short time frame.

Let’s say you applied for a job 4 months ago - then applied again today. In both instances, you were not an employee of the company. You were a candidate. By definition, you are not subject to the policies of a company if you are not their employee. If they want you to work there even if you “violated” their rule about how often to apply, then they are not excluding you for your transgression…

If you have been offered a job, accept it - or don’t. Ignore how often and when you applied.