Complex sentence: The yeshiva was founded in the 1970's by Rabbi Zilberman, an orphan who thus did not grow up forced into one sect of ultra-orthodoxy, sought to find the most accurate stream of Judaism.
Split into simpler sentences: The yeshiva was founded in the 1970's by Rabbi Zilberman. As he was an orphan, he did not grow up forced into one sect of ultra-orthodoxy, and was able to search independently to find the most accurate stream of Judaism.