According to analysis by the NBA website, hoopshype.com, Nike has 284 NBA players under contract. That's more than triple the 77 players endorsed by Adidas. Jordan, also owned by Nike Inc, has 35.
Other brands with multiple endorsements include Peak, 11; Under Armour, 11; Reebok, 4; Li-Ning, 4; Anta, 3; Spalding, 2; and And 1, 2. Those with one contract are Ball'n, 361 Degrees, New Balance, Qiaodan and Brandlblack.
The full list is here.