DNA tests are not banned in Israel, they don’t play a primary role in the repatriation process. Merely being 100% Jewish based on test results does not guarantee entry into the country. However, DNA tests are helpful if you have a relative with Israeli citizenship and need to prove your familial relationship.
Approximately 1/3 of Israel’s Jewish population is Ashkenazi (full or partial)—— “Ashkenazi Jews in Israel refers to immigrants and descendants of Ashkenazi Jews, who now reside within the state of Israel, in the modern sense also referring to Israeli Jewish adherents of the Ashkenazi Jewish tradition. They number 2.8 million (full or partial Ashkenazi Jewish descent)” Source— Hebrew University.