I think, may be that's more of a question to John.
While in conference call, I heard a person said the above sentence.
Can anyone please correct the grammar in the above quoted sentence?
It's conversational and elliptical, and means "Perhaps John is the better person to ask" either because John would know the answer or it's in John's area of responsibility, or something along those lines.
A very wooden paraphrase of the syntax, to show how that meaning is derived, would be "That is a question more like the questions which are asked of John".
I think, maybe that's more of a question to | for John.
Most speakers would choose for I think, but to John would mean "to pose to John".
To add on to Tᴚoɯɐuo's answer:
The more idiomatic expression would be:
That's more of a question for John.
which is to say, "John would be better at answering that than I would".
It's possible that the speaker was thinking of a different way to express this same idea, using a verb that takes the preposition "to":
That's more of a question (which you should direct) to John
or the passive:
That's more of a question (that should be directed) to John
or various other possibilities.