Ruling on forming a row between the pillars of the mosque
Question

In the rows in which there are pillars in the mosque, during a congregational prayer, is it permissible for me to stand on my own on the other side of the pillar?
Praise be to Allah.It was narrated that it is not allowed to form a row between the pillars of the mosque, because they interrupt the rows.
Ibn Majah, 1002, narrated from Mu`awiyah ibn Qurrah that his father said: We were forbidden to form a row between the pillars at the time of the Messenger of Allah (blessings and peace of Allah be upon him), and we would be pushed away from them forcefully. Classed as authentic by al-Albani in Sahih Ibn Majah.
At-Tirmidhi, 229, narrated that `Abd al-Hamid ibn Mahmud said: We prayed behind one of the governors, and the people compelled us to pray between two pillars. When we had prayed, Anas ibn Malik said: We used to avoid this at the time of the Messenger of Allah (blessings and peace of Allah be upon him). Classed as authentic by al-Albani in Sahih at-Tirmidhi.
Ibn Muflih (may Allah have mercy on him) said:
It is disliked (makruh) for one who is praying behind an imam to stand between the pillars. Ahmad said: That is because it interrupts the row,
End quote from al-Furu`, 2/39.
But if there is a need to form a row between the pillars, because the number of worshippers is great and the mosque is too small, then it is not disliked in that case.
The scholars of the Permanent Committee for Ifta’ said:
It is disliked (makruh) to stand between the pillars if they interrupt the rows, except in the case when the mosque is too small and the number of worshippers is great.
End quote from Fatawa al-Lajnah ad-Da’imah, 5/295.
Shaykh Ibn `Uthaymin (may Allah have mercy on him) said:
Forming a row between the pillars is permissible if the mosque is too small, and some of the scholars narrated that there was consensus regarding that. But when there is plenty of space, there is a difference of opinion concerning it, and the correct view is that it is not allowed, because it leads to the rows being interrupted, especially when the pillars are wide. End quote.
So if the mosque is too small and the number of worshippers is great, there is nothing wrong with forming rows between the pillars.
Based on that, if you come to the mosque and find that the people are standing in a row, and you cannot find any place in the row except on the other side of the pillar, there is nothing wrong with that, and this is not the same as standing behind the row on your own in the prayer, because you are not standing behind the row; rather you are standing in the row with the other worshippers, but the row has been interrupted by the pillar because there is no way to avoid that.
And Allah knows best.