Ancient Observance
There was no Simchat Torah celebration in biblical Israel. The festival had not yet developed.
Public reading of the Torah, however, has much older roots. Deuteronomy describes a public reading before the whole community at appointed times. Nehemiah describes Ezra reading the Law to the people after the return from exile.
Jewish communities continued to read Scripture publicly in later centuries. Synagogue worship gave Torah reading an increasingly important place.
The annual cycle familiar today developed after the biblical period. The custom of celebrating its completion came later still.
For this reason, we should not picture Jesus or the people of the Second Temple period celebrating Simchat Torah in its modern form. The festival belongs to a later stage in the history of Jewish worship.