The crush occurred in Kikwit, around 500 km from the capital Kinshasa on Friday.
Residents in eastern India have embarked on violent protests after a train killed 34 people on Monday.
The driver of one of the trains was still unaccounted for and thought to be inside the wreckage.
The 52-year-old train driver is expected to face charges of reckless homicide.
The magistrate formally charged Garzon with 79 counts of homicide and numerous offences of bodily harm.
The driver of a Spanish train that derailed at high speed killing 78 people has left hospital.