John Wilkes Booth’s leap from the president’s box to the stage after shooting Lincoln.
Image Source: LOC
The Leap 4
The History Behind Lincoln's Assassination
John Wilkes Booth’s leap from the president’s box to the stage after shooting Lincoln.
Image Source: LOC
LincolnConspirators.com 
I get the idea that Booth lept from the right hand side of the box , as you face it from the stage , (more toward Lincoln) , but i don’t know this for sure. Is it known which part of the balustrade he went over ?
Eyewitnesses are conflicted over which portal Booth leapt through. The wounded President may have made it difficult to push through on the right side, and we know that Booth grappled with Rathbone who viewed the play through the left portal. I don’t think we have a definitive answer for that.