Free legal aid was inserted in our Constitution by which Amendment?

The 1976 amendment of the Constitution inserted Article 39-A in the Constitution which is as follows: equal justice and free legal aid The State shall secure that the operation of the legal system promotes justice, on a basis of equal opportunity, and shall, in particular, provide free legal aid, by suitable legislation or schemes or in any way, to ensure that opportunities for securing justice are not denied to any citizen by reason of economic or other disabilities. Article 39A of the Constitution - inserted by the 42nd Amendment Act in 1976.