In 1961, what was the Chassis when the points were lower than 6?
CREATE TABLE "complete_formula_one_results" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);
SELECT "chassis" FROM "complete_formula_one_results" WHERE "points"<6 AND "year"=1961;