Coordination Compounds Part 2

Since, the compound is octahedral, the central metal M will form 6 bonds. On reaction with excess of AgNO3, only 1 mol of AgCl is precipitated that means only 1Cl− is present as counter ion and 2Cl− ions are present in coordinatesphere.
So 'L' should by bidentate to form an octahedral complex alongwith 2Cl−ions. [MCl2L2]‌Cl