What does mean when someone says commit harry carry?

While pronounced "harry carry", it's spelled "hara-kiri" (also called seppuku) -a ritual suicide by disembowelment practiced by the Japanese samurai or formerly decreed by a court in lieu of the death penalty.

Seppuku is the honourable method of taking one’s own life practiced by men of the samurai (military) class in feudal Japan.

The word hara-kiri (literally, “belly-cutting”), though widely known to foreigners, is rarely used by Japanese, who prefer the term seppuku (written in Japanese with the same two Chinese characters but in reverse order).

The proper method for committing the act—developed over several centuries—was to plunge a short sword into the left side of the abdomen, draw the blade laterally across to the right, and then turn it upward.

Samurai committed seppuku for a number of reasons, in accordance with bushido, the samurai code of conduct. Motivations could include personal shame due to cowardice in battle, shame over a dishonest act, or loss of sponsorship from a daimyo. Often times samurai who was defeated but not killed in battle would be allowed to commit suicide in order to regain their honor. Seppuku was an important act not only for the reputation of the samurai himself but also for his entire family's honor and standing in society.

Sometimes, particularly during the Tokugawa shogunate, seppuku was used as a judicial punishment. Read more at ThoughtCo.com.