Thank you very much for your question. It is our pleasure to answer it.

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright.

Dear brother, the Sunnah is for the imam to stand in the front, in line with in the middle of the row, then the rows should start from behind the imam, not from the right hand side of the mosque or the left, as some people do. Rather they should start from behind the imam, then the row should be completed to both the right and the left, so as to follow the Sunnah of having the imam in the middle.

And Allah Knows best.