Asteroid 6311 Porubcan is a main belt asteroid with an estimated diameter of 10 km. It was discovered on September 15, 1990 by H. E. Holt, at Palomar. The semi-major axis is 2.03 AU, the eccentricity is 0.225 and the inclination is 5.17 degrees.
This asteroid was observed on 7 nights between November 2004 and January 2005. The resulting lightcurve was very noisy due to background stars, and no reliable period could be derived.