The 19-year-old defender joins from CS Fola Esch, and will link up with Boro's Under-23s.
Academy Manager Craig Liddle said: "We're delighted to welcome Enes to Boro.
"He's a young defender with a good amount of experience for a boy of his age. He's a very quick, strong and aggressive defender. Technically he handles the ball well and has good distribution.
"Initially we see him coming into the Under-23 group and settling into the club while developing himself and the young players around him."