if i buy a iphone 15 while being aboard does it come with a sim tray

Models sold outside the US will have an eSIM and one Nano SIM slot.

Models sold in China, Hong Kong and Macau will have a dual Nano SIM slot.

If this important......you might want to remember that an iPhone purchased abroad will have no warranty in the U.S.....and vice versa.

That's not a problem.....unless....the phone requires service.