mañcāḥ kriyantāḿ vividhā
malla-rańga-pariśritāḥ
paurā jānapadāḥ sarve
paśyantu svaira-saḿyugam
mancah -- stages; kriyantam -- should be built; vividhah -- various; malla-ranga -- a wrestling ring; parisritah -- surrounding; paurah -- the residents of the city; janapadah -- and the residents of the outlying districts; sarve -- all; pasyantu -- should see; svaira -- voluntarily participated in; samyugam -- the competition.
The word mancah refers to platforms constructed with large pillars. Kamsa wanted a festive atmosphere so that Krishna and Balarama would not be afraid to come.