Name the most margin for nco party and p. ramachandran won
CREATE TABLE "list_of_elected_m_ps" (
  "constituency" text,
  "winner" text,
  "party" text,
  "margin" real,
  "runner_up_a" text,
  "party_a" text
);
SELECT MAX("margin") FROM "list_of_elected_m_ps" WHERE "party"='NCO' AND "winner"='P. Ramachandran';