Gender: boy
When i searched for J. Geller only three people came up and only one was a boy born between the years 1921 and 1927. The name was Jonatan Geller born 1927 and lived at KREUZ 9 15.
Jonatan Geller worked in the Lodz ghetto at "Talon-Abteilung" and he worked as a "Bote." His worker number was 66861 and according to his card he lived at Kruesz 9 flat 16, and was born on 8 April 1927. I found living at the same address Abram Jakub Geller born 1896 and Gitla Laja born 1898.