In about 985 the Seljuk clan split off from the bulk of the Tokuz-Oghuz , a confederacy of nine clans long settled between the Aral and Caspian Seas , and set up camp on the right bank of the lower Syr Darya (Jaxartes) , in the direction of Jend , near Kzyl Orda in present day south-central Kazakhstan where they were converted to Islam .