Pradyuman was found dead with his throat slit inside the school premises on September 8, 2017.
Punjab and Haryana High Court on Wednesday rejected the bail plea of the minor, who is accused of murdering seven-year-old Pradyuman at Gurugram's Ryan International School.
On May 21, a Child Sessions Court in Gurugram had ruled that the juvenile accused in Pradyuman murder case should be tried as an adult.
The lawyer, representing the deceased student's family, Sushil Tekriwal, told ANI, "The Child Sessions Court upheld judgement by the Juvenile Justice Board that the juvenile be tried as an adult. He can be subjected to stringent and strict punishment if he's going to get convicted. We welcome it."
The accused, a Class 11 student, was arrested by the Central Bureau Investigation (CBI) last year on the charges of killing Pradyuman Thakur, a Class 2 student of Gurugram's Ryan International School.
Pradyuman was found dead with his throat slit inside the school premises on September 8, 2017.
The Juvenile Justice Board had earlier on December 20 ruled that the 16-year-old accused will be tried as an adult.