Slang for getting killed/murdered. Often used by gang members + rappers in recent history
Explanation - When someone is murdered, their loved ones(or fans if famous) put a picture of them on a shirt to honor them. When someone says they’ll put someone on a shirt, they’re planning on killing that person.
When you kill someone in the hood, their family usually puts your best picture of yourself on a shirt, so they can remember you forever. It might say the words, "RIP Ja'Quavion 1995-2018" or something of similar nature.