Nándor was born in March 1925 to his parents Israel and Malka in the small town of Orsewa in what was then Czechoslovakia, in the Carpathian Mountains. The local community was Satmar Hasidim, a virulently anti-Zionist sect. This was the environment in which he was raised. In 1939, the Ukrainian Republic took over certain regions; two years later, it was Hungary which took over. Together with his mother, who was a widow with six children, Nándor endured a particularly difficult time of his life. In 1944, they moved to Munkács, and from there they were sent to Auschwitz. His mother and three of her children were murdered there. Nándor was among the Jews who participated in the Death March. However, due to lack of food and drink, he collapsed along the way. Two days later he was found by a US Army officer, who saved his life by getting him medical attention. Once he had recuperated, he returned to Czechoslovakia, but the locals were not happy to see him.

As he looked for relatives who had survived, he learned that an uncle lived in Belgium. He made contact and set out for Antwerp. In 1946, Nándor started reading the writings of famous rabbis who supported the idea of a Jewish state. This caused him to reject his anti-Zionist upbringing. In 1947, he joined the Religious Pioneers Association. He felt the need to dedicate himself to the idea of a Jewish state. When he learned of the refusal of the British Foreign Secretary Ernest Bevin to allow Jewish refugees to emigrate to the Land of Israel, he joined Lehi, which was recruiting youths to fight the British. His commander was known as Tzefoni. He taught him firearms, explosives and mailbombing, to be used against various British officials.

In early 1948, Nándor received approval to emigrate to the United States, but the War of Independence was just beginning. He joined the foreign volunteers of the IDF, and he was sent to Marseilles, where Bnei Akiva members were undergoing military training prior to being sent to the Land of Israel. As he was about to embark on the ship, he was ordered to remain and train the next group. Thus, only in May of 1948 did he reach the land of Israel, being transferred to Pardes Hannah and from there to Sarafand (Tzrifin). Even though he begged to be sent to the front lines, he would continue to serve in an administrative capacity for the duration of the war. At the end of 1950, he returned to Belgium. His uncle then invited him to join him in Los Angeles, where they worked in business.

Nándor married Frances Bornstein, and they had two sons (one of whom passed away) and numerous grandchildren.