According to Granville Austin, the most significant contributions of India to constitution-making are consensus and accommodation.

In option 1, "Majority rule and minority rights" is not mentioned by Granville Austin as a significant contribution of India to constitution-making. Although majority rule and minority rights are important principles in a democracy, they are not specifically attributed to India in the context of constitution-making.

Option 3 states "Social revolution and Political Freedom". While social revolution and political freedom are important aspects of Indian history, they are not directly identified by Granville Austin as significant contributions to constitution-making.

Option 4 suggests an "Asymmetrical Federal structure" as a significant contribution. However, this is not mentioned by Granville Austin. Austin does discuss India`s federal structure and its unique features such as the division of powers between the central government and state governments, but there is no mention of asymmetry specifically.

Thus, the correct answer is option 2, "Consensus and Accommodation". Granville Austin emphasizes the importance of consensus-building and accommodation of diverse interests and ideas in the Indian constitution-making process, acknowledging that India`s framers were able to navigate complex religious, linguistic, and regional divisions to develop a constitution that would be inclusive and acceptable to all.