Display Support

2nd Display Support: Dual/Mirroring* 2nd Max. Resolution: 2560x1600 (x2*)

Details:* This model supports a simultaneous maximum resolution up to 2560x1600 on two external displays via Thunderbolt.

Alternately, it can support a single display up to 2560x1600 via Thunderbolt and a single display up to 1920x1200 via HDMI.

Although it can theoretically power all three external displays, as confirmed by a helpful reader, it runs too hot with three displays connected.

from:

https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-i7-2.4-15-early-2013-retina-display-specs.html

(a slightly later version has slightly different HDMI support.)