In letters submitted Tuesday, 2 people describe the April 2018 armed robbery in NYC, which the rapper testified was intended as a revenge hit on Rap-A-Lot Records and its honcho, J. Prince.

As we reported ... 6ix9ine claims members of his Nine Trey gang planned to rob JP and his people after a perceived diss, and pulled off an armed robbery on Rap-A-Lot reps in the lobby of a building.

Problem is ... the 2 people they robbed were a couple publicists unrelated to Rap-A-Lot -- a case of mistaken identity. According to their victim impact statements -- obtained by TMZ -- the attack has had a lasting, negative effect on them.

One victim, a 33-year-old male, says the incident "destroyed the normal adulthood that I was striving for." He says he was far removed from a life of gangs and guns and adds ... "never have I been so scared as a cold, hard metallic gun was pressed against my abdomen."

He claims the attack made him scared for his life, and afterward, he became a recluse who was afraid to sleep in his own home. He says he still lives in constant fear someone associated with Tekashi will be sent to "finish the job." He ends his letter by asking the judge ... "Why should this person, who nearly ended my life, be free when I am not free?"

The other publicist echoes many of the same feelings and fears. She says her entire career and lifelong dreams were destroyed as a result of "this horrific event." She says she also lives in fear each day as stories about 6ix9ine -- and his potential release -- dominate the news.

She claims she is haunted by the armed robbery, which she says makes her heart race and paralyzes her with fear on a daily basis ... and she feels like she's about to die.

The woman says she quit her job, which she was very good at, in the aftermath of the attack ... and she wants the judge to hold Tekashi responsible for ruining her life.