Pradyumna did not take part in the kurukshetra war. Balarama who taught war skills to Duryodhana, in mace (gada) was also teacher for Bhima. He was well wisher of the Pandavas and did not wanted to participate in the war. He didn't want any of his family members to fight against each other. He stated if either of the two brothers Balarama or Shri Krishna fought on behalf of any side using their weapons, then the war would finish on the first day. So Balarama and no other family members of Shri Krishna took part in the war against him.
But Satyaki was an exception who fought for the Pandava army even Krishna promised his army to Kauravas. While Kritavarman who was one of the Maharathas gave his 1 akshauhini army of Yadava clan stayed with his army and fought for Kauravas.
Abhimanyu talks with his uncle Dharma Raja before entering into Padma Vyuha in Drona Parva. He mentions his teacher pradyumna several times. There he equated him sometimes with Krishna and sometimes with his father Arjuna. If Pradyumna fought in the war behalf of Pandavas, Yudhishtira would havedirectly call upon him or plot against him. There are direct references of him from Adi Parva, Sabha Parva where he participated in Rajasuya, in Vana Parva, in Mausala Parva how he dead and how he returned back to his original abode. But Pradyumna there is no single reference that he took active participation in the Kurukshetra war.
So my conclusion is : Pradyumna did not take part in the war.
We can find the names of some Yadava warriors like Satyaki, Chekitana, Kritavarma and his son Matrikavat in the list of warriors finding behalf of two sides but there was no name of Pradyumna.