Despite many difficulties, there was one big advantage for the makers of the Indian Constitution which was absent in South Africa.

Hint:
The most part of consensus of the Indian constitution had formed during the freedom struggle that what a democratic India should look like. Later, the makers of the Indian Constitution benefited in its construction. That part was absent in South Africa.

Complete solution:
The constitution of South Africa was made after a 2 year long struggle that includes many discussions and debates in the African country. Indian Constitution makers managed the world’s lengthiest constitution without any discussion, meeting and debates, because most of discussion was held during the pre-independence years between various political parties and institutional bodies.

The drafting of Indian Constitution was done by the members of the Constituent assembly. The Election of Constituent assembly was held in July 1946 and its first meeting was held in December 1946. After it, the country divided into India and Pakistan and the constituent assembly was also divided into Constituent Assembly of India and Constituent Assembly of Pakistan.

The constituent assembly adopted the Constitution on 26th November 1949 but it came into influence on 26th January 1950. So, 26 January is marked as Republic Day of India.

Note:
 Indian Constitution has some features which makes it unique in the overall world. Such as; The Constitution has been made after more consideration of consensus during freedom struggle. So, it expresses a broad consensus and specialty of its time.

The Constitution represents the people of India and also keeps thoughts in the favor of Indian. & The constituent assembly worked in a systematic, planned and consumer for its influences.