Q:

What does "who" refer to in this logic puzzle clue?

Two seats are there between O and N, who sits third right of the one who likes Tulip

The word "who" represents what? it denotes O or N?
The full problem is shown below: 

Ten friends are sitting in two parallel rows of six seats each. One seat is vacant in each row. M, N, O, P and Q are sitting in row-1 facing South. D, E, F, G and H are facing North. Each likes a different flowers i.e. Lily, Lotus, Jasmine, Sunflower, Orchid, Hibiscus, Tulip, Marigold, Rose and Lavender.
G sits third to the right of F and likes Sunflower. Only two people sit between E and the vacant seat. E does not like Orchid or Jasmine flower. Q is not an immediate neighbour of O. N likes Lavender. The one who likes Jasmine flower faces the one who likes Marigold. The one who likes Jasmine sits opposite to the one who sits third right of the person who sits opposite to G. O is not an immediate neighbour of P. H, who likes neither orchid nor Hibiscus, does not face the vacant seat. Neither G nor F sits at any of the extreme ends of the row. P faces F. Vacant seats are not opposite to each other. Two seats are there between O and N, who sits third right of the one who likes Tulip. The one who likes Rose flower faces the one who likes Sunflower. The persons who like the Lily and Marigold are adjacent to each other. Vacant seat of row – 1 is not an immediate neighbour of P. E sits at one of the extreme ends of the row. F does not like Lily and Marigold. Vacant seat of row-1 does not face G who doesn’t sit at any of the extreme ends of the row.

A:

This question concerns the following sentence:

Two seats are there between O and N, who sits third right of the one who likes Tulip.

The questions asks "What is the antecedent of the pronoun who?"
The answer is: the antecedent of who is N.
The same question can be posed in reference to the following sentence, which, except for the substitution of different noun phrases, is identical in every respect to the one presented:

Two oysters are there between Dave and The Queen of Sheba, who sits seventh to the right of the one who likes big cars with lots of chrome-plated ornaments.

In this sentence, any reading of its structure informs us that who has as its antecedent The Queen of Sheba. In English, the last in a series is taken as the referent of a pronoun which is the subject of a subsequent relative clause; for example:

In South America, among the countries which claim the Amazon river as their border are Colombia and Peru, which is known as the birthplace of the Incan empire.

The antecedent of the relative pronoun which in this sentence is the last in the series, Peru. 
n.b.: The surrounding text is not germane to grammatical analysis of the simple sentence in question. 

