Nicky and J Balvin's 2018 collaboration on the hit song "X" has been a source of the rumors on the internet of the two artists being blood-related. To answer the question-if J Balvin and Nicky are brothers- No, they are not biological brothers, but it is certain that the two share a special bond.
During his conversation with Distractify, Balvin described Nicky as his brother. "My brother... he's my brother," he said. "Last time he called me just to check out [how I was] and that means a lot to me."
Balvin made a cameo in Nicky's TV series, El Ganador. In the episode, "The Phoenix," Nicky meets Balvin for the first time as he is trying to get inside a popular nightclub.