What does 'Ibid' mean in this context?
I believe that in this case it means the person who wrote the letter does not know the proper usage of ibid.. The proper usage of ibid. is in a bibliography or footnote to refer to the previous citation.
From the context, I would assume that the writer of the letter mentions the interview in a prior sentence, and now is trying to recall the same information.
For example:
We will be interviewing you on our show "Brightly Colored Morning Extravaganza."
You are requested to appear for ibid interview on Thursday at 7 AM.
Unfortunately, this seems to be the work of a pseudo-intellectual. I know this because, as the adage goes, it takes one to know one!
Ibid. is an abbreviation for the Latin word ibidem, which means “in the same place”. It's commonly used in endnote/footnote citations, where it means “The information cited came from the same book as the previous citation.“
It's unusual (and, I think, ungrammatical) to use ibid as an adjective, but in this context, I'd assume the writer intended it to mean “above-mentioned” or “aforementioned”. That is, your quotation is referring to an interview which the writer had described slightly earlier in the letter.
Going out on a limb, I see someone who tried to replace the typical Indian-English use of "the same" or "same" by something they thought was "more proper" English.
As a result, they managed to create something that is not only ungrammatical, but also semantically puzzling.
I would have no problems understanding this line in an Indian-English context if it were written as:
We have planned an interview [...] and you are requested to appear for the same.
Interestingly, this is why I am weary of questions asking for replacements of standard (localized) expression, like "what is better alternative for do the needful.
Someone looked up an alternative for "the same" and found "ibid.", which can indeed be an alternative in some cases.
Thinking it looked better than the "Indianism", they ended up mangling their sentence :)