Regarding the cross in the photo here, Hartgen Archaeology has written in a May 2014 report "An approximately 10-ft (3.0 m) tall concrete cross is lying on the ground outside of the northern edge of the cemetery. However, the size and concrete and iron rebar construction suggest that it is associated with the 20th-century former Immaculate Conception Monastery to the south and not the cemetery." Part of the former site of the cemetery is in the upper right of the photo - the hillside south of the dirt road.

"A petition from the inhabitants of the sixth ward was presented by Alderman Ford, requesting the Common Council to provide a piece of ground in the 6th ward for a public burial ground, was referred to the burial ground committee, and Alderman Ford to inquire and report."
“Common Council Proceedings.” Troy Daily Whig. January 20, 1835: 1 col 5.

"The Sixth Ward Cemetery, on the hill-side west of Vandenburgh Avenue, near the Burden Iron Company’s upper works, is a small plat of ground, which was conveyed May 17, 1836, to the city by the Troy Nail Factory Company, to be used as a public burial ground for that part of the city."
Weise, Arthur James. The City of Troy and Its Vicinity. Troy, NY: Edward Green, 1886. 55.

"The Sixth Ward Burying Ground is being improved under the recent order of the Common Council. Roads and walks are to be laid out, and the grade improved."
“Home Matters.” Troy Daily Times. June 22, 1853: 2 col 3.

"By Ald. Maloney—Petition of Thomas B. Cook and about fifty others asking for the repairing of the fence around the burying ground in the sixth ward. [Burial grounds."
“Common Council Proceedings.” Troy Daily Times. October 19, 1883: 4 col 3.

"Cows and pigs continue to roam over the graves in the old sixth ward burial ground. The fence recently ordered by the common council has not yet been begun."
"From the Southern Section." Troy Daily Times. November 21, 1883: 3 col 3.

"There is now no sixth ward burying ground. The bodies are supposed to have been removed to other burial grounds."
Municipal Ordinances of the City of Troy. Troy, NY: Troy Times Art Press, 1905. 219.

Hartgen's 2014 report stated in part, "grave shafts were uncovered about 12 inches (30.5 cm) below the current ground surface. Hartgen did not explore the shafts by digging deeper. Also, no human remains, traces of coffins, or coffin hardware were found. This suggests that the burials are intact and have not been disturbed by subsequent activities." Thus, while some reinterments to Oakwood Cemetery, New Mount Ida Cemetery, and perhaps other cemeteries occurred, there's evidence to suggest that the cemetery was not removed in its entirety.

Many interments for 1850-1884 can be found in the Troy Superintendent of Burial Grounds' interment records. Burial permits and church records might provide other sources?